344 bulletin: museltvi of comparative zoology. 



mex sanguineus was found only in termitaria, usually in the upper 

 portions, but often tlu-oughout the structure. At Koah I found also 

 three species of Polyrhachis of the subgenus Charioviyrvia {cyrus, 

 senilis, and comata) and Camponotvs (Myrmogonia) ruhiginosus in the 

 smaller termite nests, the former frequently, the latter as a regular 

 inquiUne. It builds on the surface of the termitarium a small, chimney- 

 like entrance, which is guarded by one of the large-headed major 

 workers. Euponera (Brachyjjonera) lutea and two forms of Campono- 

 tus (Myrmoturba) mamlatus are also occasionally found in termitaria 

 but nest much more frequently under stones and logs. 



Not only is 0. haddoni a regular inquiline in the nests of another 

 insect, but it seems to be itself the host of other species of Opisthopsis I 

 In several of the nests at Koah I found from one to six very dark 

 browTi or black workers among the bright yellow haddoni. In my 

 opinion they belong to two distinct species, which are described below 

 as 0. maurus and lienosus. The fact that they occurred in haddoni 

 colonies in which males and females were hatching, would seem to be 

 fatal to the view that they are true parasites. That they are very 

 aberrant or diseased workers of haddoni seems to me improbable, 

 because the workers of this species are very constant in coloration 

 and because the dark indi"viduals exhibit peculiarities of form and 

 sculpture as well as of color. I believe that haddoni, like many other 

 ants, may occasionally kidnap the brood of alien species and that the 

 dark indi\'iduals may have been reared from cocoons thus procured. 



The males of Opisthopsis seem not to have been seen by previous 

 observers and the females of only a few of the species have been 

 described. The males are of the same size as the workers and very 

 much like the males of Camponotus, with which genus Opisthopsis 

 is evidently very closely related. Forel, in a recent classification of 

 the subfamily Camponotinae, places Opisthopsis in the tribe Cam- 

 ponotini and shows that its proventriculus (" gizzard ") has essentially 

 the same structure as in Camponotus, being long and slender, with a 

 straight, i. c. nonreflected calyx (Plate 3, fig. 29). Opisthopsis can- 

 not, however, be regarded as an offshoot of the genus Camponotus, 

 owing to the fact that the former has a discal cell in the fore wing. 

 This represents a more primitive condition than in Camponotus, 

 where the discal cell is always absent. We must conclude, therefore, 

 that both Opisthopsis and Camponotus have had a common origin 

 from some more ancient, extinct genus with a venation more like that 

 of Formica. Attentive examination of the workers of Opisthopsis 

 shows that they have a feeble tendency to dimorphism in the shape 



