MUTILLA. 261 



Paleearctic and Oriental Mutillidse might not apply to the Neotropical forms. The 

 males could be separated by the number of the cubital cellules, which range from one 

 to four, but this will not aid us with the females. In my opinion Sphcerophthalma, 

 Blake, should be accepted as distinct from Mutilla — the circular, convex, shining eyes 

 alone serving to separate it from Mutilla, the eyes in the latter being oval, larger, 

 and duller. Splicer ophth alma and Mutilla are divisible, in both sexes, into two well- 

 marked groups by the form of the basal abdominal segment : in the one case it forms 

 a distinct peduncle, quite distinct from the second segment, to which at the apex it is 

 not equal in width ; while in the other section the first segment becomes gradually wider 

 to the apex, and is equal in width to the base of the second and continuous with it. 

 These differences are so apparent that they might be used as marks of generic distinc- 

 tion ; in fact, they have been so used by Kadoszkovsky (Horse Soc. Ent. Koss. xix. 

 p. 32), who reserves the name Sphcerophthalma, Blake, for the division with the 

 " abdomen petiole, premier segment ne plaquant par le suivant," the males having 

 three cubital cellules ; and for the section with the " abdomen subsessile, premier 

 segment plaque avec le second," he creates a new genus Edrionotus, the males of which 

 are said to have only two cubital cellules. For another group with round eyes he has 

 proposed (op. cit. p. 35) the genus Tricholabiodes, this having the "corps allonge, 

 premier segment abdominal long, subpedoncule, ne plaquant pas le suivant, tete 

 transversale, yeux ronds"; the wings with three cubital cellules. Only males are 

 known. 



It is worthy of remark that, so far as we know, all the males of the first division of 

 Mutilla— that with the basal abdominal segment gradually dilated to the apex — have 

 the abdomen entirely or for the greater part ferruginous, all the segments, too, being 

 densely fringed with fiery-ferruginous hair ; the petiolated section, on the other hand, 

 having the abdomen, except in a few species, black, with white hair. In the first 

 division also the system of keels, spines, &c. on the apical abdominal segment is much 

 better developed. This fact, among others, inclines me to the view that the two sections 

 ought to be separated generically, but I am reluctant to make this division without a 

 comprehensive study of the species from other parts of the world. 



As a matter of convenience, when only the males of a species are known, I have 

 placed them together. 



MUTILLA. 



Mutilla, Linnajus, Syst. Nat. 12th edit. i. 2, p. 966 (1767). 



This genus shows much less diversity in the form and structure of the head and 

 thorax than does Sphwrophthalma ; it has the body much less hairy, and the number 

 of species, at least in the Neotropical region, is much fewer. 



