112 PECKHAM. [Vol.1, 



this case the disguise of the spider would enable it to approach 

 the beetle without arousing suspicion. While I give this as a 

 possible explanation, it is improbable that any such disguise is 

 necessary in order to capture beetles, and I think it most likely 

 that the object of the mimicry is to preserve the spider from 

 some enemy that would rather eat spiders than ants. 



To sum up the peculiarities of picata — it is ant-like in 

 form and color; it moves like an ant and holds up its second 

 pair of legs to represent antennge; it is found among ants, but 

 neither eats them nor is eaten by them. 



Synemosyna formica (fig. 12) agrees 

 in all respects with picata, unless it is in 

 the zig-zag walk ; upon that point I am 

 unable to speak with certainty. Of 

 formica, which is more ant-like in form 

 and color than picata, Hentz says ; " I 

 had seen individuals of this species run- 

 ning on the blades of grass and stems of 

 weeds long before 1 distinguished them 

 Fig. 12. -Synemosyna ^^m aiits. They movo with agility and 

 Mr^ Kumh'^nr*''''' '''' Can leap, but their habitus is totally dif- 

 ferent from Attus. They move by a reg- 

 ular progression or regular walk, very different from the 

 halting gait of that subgenus."* 



Both formica and picata hold the second pair of legs like 

 antennee. Many of the ant-like Epeiridse from South America, 

 seen in collections, have palpi that look extremely like anten- 

 nae, while their long legs can only be useful in locomotion. 

 Belt speaks of a spider in Nicaragua which holds up its first 

 legs like antennse and moves them about like an ant. He also 

 says that in one spider the palpi are lengthened and thickened 

 so as to resemble an ant's head. The following quotation 

 from J. P. M. Weale, shows that some African ant-like species 

 also hold up their first legs : "The most perfect cases of mim- 



"Loc. cit.. p. 73. 



