2 
J. H. Tull Walsli — On certain Spiders which mimic Ants. [No. 1, 
the Attidoe. These spidors, ant-like in form, and partially ant-liko in 
habit, do not spin webs for the purpose of catching prey, but, wandering 
about in company with the ants they resemble, spring upon their vic- 
tims from behind, (hence called by some Entomologists Saltigradai) . 
Their home is generally fixed to the under surface of a leaf and consists 
of a small oval, whitish, silky nest just big enough to accommodate the 
spider. Attention has been drawn to the presence of these spiders in 
America* and Africaf ; Mr. Wood-Mason collected two or three speci- 
mens in Assam some years ago and Mr. ItothneyJ notes the occurrence 
of a Salticus in company with Sima rufo-nigra in the neighbourhood of 
JBarrackpur. I have found these spider mimics in Orissa, and also in 
and near Calcutta, and have, during the last eighteen months, collected or 
acquired some eight or ten species or varieties belonging to genera of 
the sub-family Attidce. With one or two exceptions all these spiders 
were found hunting with the ants they so closely resemble. The two 
most common are a variety of Salticus formicarius Linn, which mimics 
Sima rufo-nigra Jerd. and a pretty Salticus (sp. ?) which may bo found in 
company with Ocophylla smaragdina Eabr. whoso nests are extremely 
common on the trees in the Royal Botanic Gardens at Sibpur. 
The resemblance in form and colour is so great that collectors 
havo been deceived, and indeed except with a lens it is difficult often to 
say which is the ant and which is the spider ; but at the same time it 
must be remembered that the likeness is greater when both are alive 
and moving than when the dead spider is compared with the dead ant. 
While the body in most sub-families of spiders is short and rounded 
with a constriction only between the cephalothorax and the abdomen, 
the mimic has a long thin body like that of an ant. There is a partial 
constriction marking off the cephalic from the thoracic portion of the 
cephalothorax, and that part of the spider’s body which joins the cepha- 
lothorax to the abdomen is drawn out into a pedicle having on its upper 
surface nodes mimicking closely thoso on a ant’s pedicle. The colour- 
ing of the spider is also a more or less correct imitation of that of the 
ant. A superficial resemblance could hardly go farther, but there is a 
still more wonderful point to notice. The spider has four pair of legs 
and no antennse ; the ant has three pair of legs and a pair of long an- 
* Bates, Trans. Linn. Soc. Yol. XXIII. 
Belt “ Naturalist in Nicaragua,” p. 314. 
Peckham Protective Resemblances in Spiders.” I have not been able to read 
this in the original and know of it only from references found in Poulton’s “ The 
Colours of Animals.” 
t J. P. Mansel Weale Nature Vol iii. p. S08. 
t Jour. Bomb. Nat. Hist. Soc. Vol. V, p, 44. 
