ME. R. I. POCOCK — MIMICRY IN SPIDERS. 261 



immature and moulting males have similar habits and, like the females, have 

 the carapace and legs light brown and the abdomen smoky. But the adult 

 males roam about the veldt bv day and are totally different in colour, 

 imitating in this particular as well as in movement the smaller specimens 

 o£ a large vicious ant {Camponotus fulvopilosus) which is common in the 

 locality. This similarity is not apparently effected by any special structural 

 modification, the fore part of the carapace being normally rounded and rather 

 sharply differentiated from the posterior portion, thus giving to the carapace 

 a constricted appearance suggesting the head and thorax of an ant — the 

 narrow waist^ small abdomen, and longish slender legs of the spider, carrying 

 the body well off the ground, completing the resemblance to the insect. The 

 latter, like the spider, has the carapace and legs black, and moves in a series 

 of rushes *. 



In the Drassidse two instances of mutilloid mimicry have been noticed in 

 Rhodesia by Guy Marshall j. The species are MelanopJwra (Prosthesima) 

 albomaculata and lltus lugens, which present a general resemblance to 

 Mutillas. 



Mutilloid mimics are also found in Coenoptyclms and Graptartia, two 

 Ceylonese genera belonging to the family Ckibionidfe. Both colour and 

 shape combine to effect the likeness. The carapace is red in colour, 

 rounded above and parallel-sided ; while the abdomen, like that of the 

 above-mentioned Drassidse, is black and ornamented with white spots. This 

 family — the Clubionidas — furnishes some of the most perfect cases of ant- 

 mimicry known, the most specialized forms of all being referable to the 

 South American genus Myrmecium. The carapace is marked by a deep 

 constriction behind the point of insertion of the legs of the second p:iir — the 

 part in front of the constriction representing the head, and the part behind 

 it, which is long and narrow and laterally bilobed, the thorax of the ant. The 

 posterior extremity of the carapace is prolonged into a narrowed neck, which 

 with the pedicel and a similar short prolongation from the abdomen exactly 

 reproduces the waist of the insect. The abdomen is evenly oval or shallowly 

 constricted. The colour varies according to the species of ant that is 

 imitated. Myrmecium nigrum (fig. 3), which mimics Pacliycondyla villosa, 

 is black and clothed with close-set yellowish-green pubescence, and the 

 abdomen is marked behind with transverse bands simulating segmentation. 

 Other species are yellow or red, with the abdomen striped brown or black, 

 to resemble species of Megalomyrmex. Others are black with yellow legs, 

 in imitation of ants of the genera Atta or Anochetus ; others, entirely brown 

 and furnished with extra pubescence, reproduce exactly the form and colour 

 of Dendromyrmex fahricii. 



* C. C. Schreiuer, Pop. Sci. Monthly, Dec. 1902, p. 162 ; Purcell, Ann. S. Afr. Museum, 

 1903, p. 32. 

 +;^Tr.'Ent. Soc. 1902, p. 511. 



