In the familjr Attidse, as in several other famihes of Arachnida, there is a group of spiders whose members are remarkable for their resemblance to ants. Some of the species of this group are found in the subfamily Attinse (Attidfe having the eyes arranged in three rows), and some in the subfamily Lyssomanse (Attidte having the eyes arranged in four rows). In many cases the likeness to ants is rendered striking by a constriction of the cephalothorax or of the abdomen, by which the body seems to be made up of three segments instead of two. Sometimes both cephalothorax and abdomen are constricted. Of all the American Attidse Synemosyna formica is the most antlike ; and it would seem that in this genus the differentiation toward an antlike form has reached its highest point.
ANT-LIKE OEOME V AND ELIZABETH MILWAUKEE FECKUAD : Natdeal History Society of Wisconsin PRESS OF B, AiKENs & Cramer, ILWAUKEK, WIS ANT-LIKE SPIDERS OF THE FAMILY ATTID.E GEORGE W AND ELIZABETH PECKHAM G Introduction In the familjr Attidse, as in several other famihes of Arachnida, there remarkable is for their a group of whose members are spiders Some resemblance to ants of the species of this group are found in the sub-family Attinse (Attidfe hav- ing the eyes arranged in three rows), and some in the sub-family Lyssomanse In many (Attidte having the eyes arranged in four cases the likeness to ants rows) rendered striking by is a constriction of the cephalothorax or of the abdomen, by which the body seems to be made up of three segments instead Sometimes both cephalothorax and abdomen are conof two Of all the American Attidse Synemosyna formica is stricted the most ant-like ;* and it would seem that in this genus the differentiation toward an ant-like form has reached its highest point The leg formula in the ant-like Attidee varies but slightly The fourth pair the first is is slender, without pair is is much in other Attidse, more much difference in size The ; legs are usually occasionallj' the first thickened, and less often, the second There sexes, almost always the longest, but in a few cases longer than the fourth less diversity in color in and there is this group than between the also less difference although in the males of some species the integument is and the first legs are larger than in the females and in some genera, as Salticus and Paradamoetas, it is common for the males to have long, horizontal falces, while The colors are those of the females are short and vertical iridescent ; *0f this species Hentz (Spiders of the United States, p 73) says : " I had seen indi- viduals of this species running on the blades of grass and stems of weeds long before I them from ants They move with agility and can leap, but their habitus is totally different from Attus They move by a regular progression or regular Avalk, very In a former paper we stated that dift'erent from the halting gait of the sub-genus." Synemosyna formica, like Synageles picata, holds up its second pair of lees to look like antennae This is an error It is with the first, not the second, pair of legs that formica mimics the antennjc of ants distinguished PECKHAM [Vol 2, browns and blacks with white bands, and sometimes with orange or red, Uke that seen in ants and there is a close usuall}' ; similarity in general appearance, so that the determination of genera and species The some rendered very is species, notably in those palpus difficnlt palpi of the males are not especially variable In certain species of palette-shaped in both sexes is Synemosyna the In of Salticus, the tarsus of the end of the venter has a hard plate, extending from pedicle to epigynum and sometimes the integufront ; ment is also more or less hardened on the upper surface of the abdomen The mm ant-like Attidse are usually small, averaging about in reaches 11 although we have length, mm They and bushes, or on the plants one species which commonly found running on ground in hot, stony places They are Synageles no snares which we kept in confinement, made a little, tubular nest, into which it retired during the colder parts of the da,j The few species that we know in life mimic the movements as well as the form and color of ants.* Of one of these " While picata is antspecies we have said in a former paper like in form and color, by far the most deceptive thing about it is the way in which it moves It does not jump like the other Attidte, nor does it walk in a straight line, but zig-zags continuall}^ from side to side, exactly like an ant which is out in search of booty This is another illustration of what Wallace has shown in relation to butterflies that that which is an important functional structure in the mimicked group are like other Attidis in spinning picata, : — may be in this way when straight line " pair ; but it in it perfectly useless is hunting its little In addition to of legs its at other times it goes in a ant-like walk, picata holds up its second such a way that they look like antennse is true also of Central American and African See Bett's Naturalist in Nicaragua, Vol III., p 508 ; imitator zig-zags always *AccorcIing to other observers this species when the habits The ant only moves imitated by the mimetic species, even of the latter render p 314, and J P M Weale in Nature, 1871, No ANT-LIKE SPIDERS OF THE FAMILY ATTID.E 1.] The legs are short, first The second body pair, and support the anterior part although it is All the threatening and not to be needed for locomotion movements made by other spiders with the are with picata made with the second first pair, Spiders commonlj' remain nearly motionless while they are eating is of the sometimes used, seems similar " picata, ; on the other hand, acts like an ant which engaged in pulling some treasure-trove into pieces convenient carrying for have noticed a female picata which, I getting possession of a gnat, kept beating as she ate, pulling it and after with her front legs about in different directions, and twitching her ant-like abdomen Drassidse it all the time Pavesi says that the ant-like Attidee continually move abdomens exactly their as ants do."* The pairing of these spiders, so far as habits of Synageles picata, sexual difference is we have found, In our study of the mating takes place outside the nest we say " : The most important the greater thickness of the first legs of the These are flattened on the anterior surface and are of male a brightly iridescent steel-blue Unlike most of the Attid color males, picata keeps all his feet on the ground during his court- ship raising himself on the tips of the posterior six he slightly ; head downward by bending his front legs, their convex surface being always turned forward His abdomen is inclines his lifted vertically so that it is at a right cephalothorax After a angle to the plane of the In this position he sways from side moment he to side drops the abdomen, runs a few steps nearer the female, and then tips his body and begins to sway again Now he runs in one direction, now in another, pausing every few moments to rock from side to side and to bend his brilliant legs so that she may look full at females in the box and saw each, after a time, made them * him mate with * * all of ^^e had six them and ; a cocoon containing three large eggs."t *Proteetive Resemblance in Spiders, Occ Papers of Natural Hist Soc of Wisconsin, Vol 1, No 2., p 110 tSexual Selection in Spiders, Oce Papers of Nat Hist Soc of Wisconsin, Vol No 1., p 43 1, PECKHAM We afterward [Vol 2, found that a female picata commonly made some of them containing three and some four eggs Synemosyna formica has probably about the same rate of reproduction, since we once found a cocoon of that three cocoons in a season, Figs and 2.— Syuageles picala species containing four eggs Positions of male approaching female AVe have elsewhere called atten- tion to the low fertility of the ant-like sjsiders (some species of Attidfe lay 180 eggs), and, have suggested that inverse variation in every species between its if is an and its there birth-rate powers of maintenance, we must accept the conclusion that Fig these small, — Synageles picala weak and Side view of male approaching female defenseless spiders derive advantage from their imitation of ants, their an immense mimetic form enabling them to escape from their enemies About one hundred described found in almost live in have been somewhat peculiar They are of the world, and seem as well able to species of ant-like Attidse Their distribution all parts is one climate as in another, but it is in two widely sepa- No 1.] ANT-LIKE SPIDERS OF THE FAMILY ATTW.F rated regions that they I'cach their greatest genera and species; they are very development of much more numerous in South America and in the Malay Archipelago than in any other countries The only suggestion that explanation of this uneven distribution we can that is ofter in the tropics abov;nd in small spider-eating birds, and that the mimetic form is hei'e of the greatest value in enabling the little spiders to escape from the birds under the guise of ants In the following paper we have used twenty genera, of which fourteen are new As the clypeus, falces and legs vary considerably in the species of one genus, and even in the sexes we have thought it best to base our classificaon the general form of the cephalothorax, and on of one species, tion mainljr the size and disposition of the eyes AVe wish to acknowledge our indebtedness to the well- known traveler, Mr Herbert H Smith, able collection of South for many places; American for the u.se of his valu- Attidse ; to Mr Eugen Simon, interesting specimens from Ceylon, and like Attidse tions are all to Mr .J H Emerton, which he has placed from nature, bj'^ the at Luzon and other for several figures of ant- our disposal skillful hand Our of Mr illustra- Emerton PECKHAM We append a [Vol 2, of the ant-like Attidae soTar as published, list not including those described in this paper: Agorius gracilipes female Ragni Mai Damoetas nitidus male Th., 1877 Pap e, I., L K., 1879 Arachniden Australiens, Janus atratus male Aran, de Celebes p 217 p 1070 Tacz., 1874 la Guyane cayennensis male Francaise, p 92 Tacz., 1874 lb p 90 longulus male Tacz., 1874 lb p 87 Tacz., 1874 lucasii female lb p 96 melanocephalus male G K., 1846 Die Arachn, XIII., mutillaiformis male Aran, du Perou, obscurus male p 23 Tacz., 1879 p 372 Tacz., 1874 Aran, de la Guyane Francaise, p 93 Tacz., 1874 subtilis female lb p 91 Wankowiczii male Tacz., 1874 lb p 88 Leptorchestes cognatus male L K., 1879 Arachniden Australiens, erythrocephalus male lb p 1057 luctuosus male L K., 1879 lb p 1065 simoir male L K., 1879 lb p 1061 striatipes male lb p 1059 p 1063 L K., 1879 L K., 1879 No 1.] J NT-LIKE SPIDERS OF Rhombonotus THE FAMILY ATTIDjE gracilis male, female L K., 1879 lb p 1067 male Salticiis alticeps Java Th., 1890 Diagnoses Aranearum aliquot novaium in Indo- Malesia inventarum, p 27 augustus male Th., 1877 Ragni Mai bi-color male e Pap Celebes p 213 I., L K., 1879 Arachniden Australiens, Ann and Mag Nat constrictus male Proc 1055 p Camb., 1869 bi-curvatus male Blk., 1877 Royal Irish Acad., Vol discicoUis male, female Aran, du Perou, formica male Ceylon Hist., p 67 III., p Tacz., 1879 p 371 Doles., 1859 Arachn Ind Archipel., p 23, equals Synemosyna Amboina decipiens Th., 1877 formosus male, Th., 1890 Diagnoses Aranearum aliquot novarum in IndoMalesia inventarum, hesperius male Arachn E S., p 26 1887 recueillis a Assinie (West Africa) Ent Soc de France, p 261 Salticus leptognathus male Th., 1890 Java Diagnoses Aranearum aliquot novarum in IndoMalesia inventarum luridus male E S., 1885 Singapore Arachn de I'Asie Merid., melanops male III., p IS Tacz., 1874 Aran, de la Guyane Francaise, has it also p 86 Taczanowski from Peru modestus male, jun Th., 1892 Spiders from Andaman Islands, Ann and Mag Hist., p 235 paviei male E S., 1886 Arachn de Siam, p Tepong Nat PECKHAil 10 Salticus pectorosus male, female [Vol 2, Sumatra Th., 1890 Diagnoses Aranearum aliquot novarum in Indo-Malesia inventarum, p 26 Camb., 1876 repudiatus male Spiders of Egypt, Proc Zool Soc, Die Arachn., XIII., Europe p 29 Urquhart, 1884 (male) zantho frontalis male, female and 1885 p 625 C K., 1846 tyrolensis, male, female New Trans (female) Zealairid Ins., pp 45 and 203 Synageles ludibundus, male E 1876 S., Arachn de France, III., p 15 todillus male E Synemosyna France, 1869 S., Greece, 1876 Syria, Corsica, lb p 17 capito male Th., 1890 Diagnoses Aranearum aliquot novarum in Indo-Malesia inventarum, p 24 Th., 1877 clavigera male Ragni Mai e Pap I., 208 Java Th., 1890 debilis male Celebes p Diagnoses Aranearum aliquot novarum in Indo-Malesia Iteta inventarum, male p 25 Th., 1877 Ragni Birmani, lugens male p 339 Th., 1881 Ragni Mai lupata male e Pap III., p Arachniden Australiens, moesta male Th., 1877 Ragni Mai nigi-a male 406 L K., 1879 e Pap Th., 1877 I., p 1052 Celebes p 201 Celebes lb p 204 nitidissima male Th., 1877 lb p 206 noxiosa Hentz., 1867 Supplement to Hentz's Nat Hist Soc Arachn Writ., Proc Bos No ANT-LIKE SPIDERS OF THE FAMILY ATTIDM 1.] SIMONELLA BI-COLOR mm Total length, 6.8 Cephalothorax Legs, 4312 : Length, 2.8 mm.; width, 1.2 and is higher than the thoracic, Behind the dorsal eyes slightly inclined forward deep constriction, which runs on to the sides arched upward in the median dorsal part and The quadrangle ually behind than long, wider behind than in The long, slender, nodose is much rather high, is mm all slender ; The general appearance cephalic part N SP female; 5a, epigynum PI VII., Fig 5, ? 83 of the eyes front, a is falls very grad- one-fourth wider and occupies a The than one-third of the cephalothorax is is The thorax little less first row and are nearly three times as large as those of the second row; those of the third row are half-way between the second and fourth Tiie dorsal eyes are very prominent, eyes of the are close together, The standing out from the sides of the head The abdomen has a deep long middle, behind which slopes it rises pedicle is rather constriction in front of the into a rounded hump and then off Color The caput bright golden-brown, with the eyes is on black spots; there aie white hairs around the eyes and in a band around the constriction behind the constriction the color is darker and more reddish than in front, shading into ; black The black, with a tranverse band black at the pedicle; the pedicle the abdomen is near the pedicle ; has a ond The fine, black, is all white ; first end of of white hairs The leg falces, is all mouth parts and sternum tibia, which white except the longitudinal line on the inner side; the sec- and proximal the third has the coxa, trochanter half of the femur black into yellow-brown, and ; the distal half of the femur shades the other joints are white all leg has the coxa black, the trochanter white, the as in the third leg and the other joints Habitat anterior the constriction and the posterior part are pale yellow, almost white are pale yellow is ; the patella white white Venezuela The ; ; the fourth femur shaded, the tibia yellow-brown, palpi are white From the collection of M.Eugen Simon EXPLANATION OF PLATES Salticus Fig 1, falces of female ; Fig 2, Salticus epliippiatus, female 2a, side of ynura cephalotborax of female (after Fig 3, x formicarius, female ; face la, and lb, cephalotborax of female in profile x (after Emerton) Emerton) (after ; 2b, epig- Emerton) Salticus electricus, male x ; 3a and 3b, male palpus male Fig 4, Salticus simplex, Fig 5, Salticus augustus, long falces; 5b and Fig 6, 5c, Salticus male 4a, ; ; 4b and 4c, male palpus 5a, variety of male, having male palpus centralis, epigynum ; 6a and 6b, male palpus Figs 7, 7a and 7b, Salticus Fig 8, Salticus gracilis, ichneumon, male palpus epigynum PLATE " H.Emari.o!i, irom iia.tu E Orisand, lltt-iKe-wHti I Fig 1, SaU.icus gracilis, female; la, face and falces; lb, side of cephalothorax Figs and 2a, Salticus robustus, Figs and 3a, Salticus nemorensis, Fig 4, Salticus dubius, male palpus male 4a and 4b, male palpus ; Fig 5, Salticus edentulus, Fig 6, Salticus desertus Figs Fig ; epigynum male, 6a and 6b, male palpus 7a and 7b, Salticus niger, male palpus 7, 8, male palpus Salticus spissus, male ; 8a and 8b, male palpus Fig 9, Salticus spissus, variety solivagus, male ; 9a and 9b, male palpus Fig 10, Salticus imbellis, male; 10a Fig 11, paplus Salticus bellicosus, and 10b, male; 11a and male palpus lib, male PLATE J.H.Emertan, from nai II, E CnSMd, 3uh TJewH;>ven,Ct, Fig palpus ; Fig and 2, Salticus 3, male; plataleo'ides, la and lb, male epigjaium Salticus tristis, 2d, variety rufula, Fig 3c, 1, Ic, male 2a and 2b, male palpus; 2c ; male palpus Salticus providens, male ; 3a and 3b, male palpus ; epigynum Fig 4, Bocus excelsus, of cephalothorax Fig 0, ; male ; 4a, face Sarinda 6, Fig 7, falces ; 4b, side nigra, female ; 5a, face ; 5b, side epigynum; 5d and 5e, male palpus Sarinda Iseta, male; 6a and 6b, male palpus Zuniga severa, female 7a, epigynum cephalotliorax; 5c, Fig and 4c and 4d, male palpus ; of PLATE E III Cri s an d.lith, New Haven, Gt PLATE Fig ], side of cephalothorax Fig 2, IV Zuniga magna, female; ; Martella Ic, face la, and falces; lb, epigynum female pottsii, epigynum ; face 2a, ; side 2b, of Fig 4, and Martella maria, epigynum Martella opica, male 4a and Fig Leptorchestes chrysopogon, female; 5a, face and cephalothorax Fig 3, 5, ; 2c, ; 2d, 2e 2f, male palpus 4b, palpus ; falces; 5b, side of cephalothorax Fig 6, Leptorchestes georgius, epigynum Fig 7, Hermosa volatilis, side of cephalothorax; 7c, Fig 8, female; 7a, face and falces; 7b, epigynum Emertonius exasperans, male; 8a, face and falces ; 8b, side of cephalothorax Fig 9, Erica eugenia, female of cephalothorax Fig 10, ; 9c, Fluda ; ; narcissa, female side of cephalothorax ; 10c, and falces 9b, side male palpus face and falces 10b 9a, face epigynum 9d and ; epigynum ; 9e, 10a, ; PLATE J rl-EniariLOii, iroin tia.tu.y-e '£, Crisand, lica-iNevir Haver., Tv Cc Fig 1, nuni ; ; 2, Synageles thorax of young, after the side of cephalothorax of same 2h, 2f, ; Emerton) side 2a, ; Emerton) (after first young moult ; side cephalo- of 2b, side of cephalo2c, face of same moults ; ; 2d, 2e, face view of female when nearly mature (after and second legs of male (after Emerton) Fig Fig 4, (after Emerton) 2i, ; ; Marengo crassipes, 4b, side of cephalothorax Fig ; after several and second legs of female 2j, male palpus 3, Fluda ruficeps, epigynum first ; 2g, first ; epigynum falces epigynum female picata, thorax of adult female and la, face ; Synageles americaiia, epigy- Ic, Id, Synageles scorpiona, Fig of female venator, Sj^nageles side of cephalothorax lb, 5, Bellota ; 4c, formicina, and female ; face 4a, male ; oa, face and male palpus 6a, face and Fig 6, Semora napsea, female 6c, epigynum side of cephalothorax side of cephalothorax ; 5c and falces epigynum falces; 5b, 5d, ; falces ; 6b, ; Fig 7, Keyserlingella falces; 7b, side of female perdita, cephalothorax; 7c, ; 7a, and face epigynum; 7d and 7e, male palpus Figs and 8a, Keyserlingella cara, male palpus Fig 9, Descanso vagus, female side of cephalothorax ; 9c, ; epigynum 9a, face and falces ; 9b, PLATE V Z Gisand, litt.,New Haven, C Fig thorax; Fig falces; Descanso cbapoda 1, Ic, Paradanioetas 2, 2b, ; la, face of cephalo- lb, side ; epigynuin side formicina, of cephalotborax ; female; 2c, 2a, epigynum ; face and 2d, male palpus Fig 3, lola cowanii, female tborax ; 3c, ; 3a, face ; 3b, side of cephalo- epigynum Synemosyna Fig 4, formica, female (after Emerton) and side of cephalotborax, early moult; 4b, face moult 4c and 4d, side of cephalotborax and ; moult; later face and 4e, side view of adult female falces of adult (after Emerton) epigynum; ; 4g, and ; 4a, same and eyes of Emerton); 4f, face (after eyes, mouth parts of male (after (after Emerton) 4k, under side of front of abdomen of male (after Emerton) Emerton); ; 41), 4i 4j, male palpus PLATE VI E Cnsiinci, lith.,IIeV7 Haven, Ct, PLATE Fig and Ic, 1, Synemosyna VII lauretta, female; la, epigynum ; lb male palpus Fig Fig 2, 3, Synemosyna hentzii, female Simonella americana, male cephalothorax ; Figs 4, 4a, ; 3a, face ; 3b, side of 3c and 3d, male palpus 4b and 4c, Simonella myrmeciseformis, male palpus Fig 5, Simonella bi-color, female; 5a, Figs and 6a, Salticus epigynum armatus, male palpus PLATEVII J.H.Emercon, iiom n3-L E Crissuid, lith., New Haven, Ct ... say " : The most important the greater thickness of the first legs of the These are flattened on the anterior surface and are of male a brightly iridescent steel-blue Unlike most of the Attid... white hairs on the around the constriction the eyes of the first The upper surface medium brown, the of the first legs much femoral and second pairs are darker than the other The third and fourth... with a row of teeth along the inner side of each these teeth grow the fang is larger as they approach the insertion of the fang nearly as long as the falx Lip longer than wide Coxte of Sternum