218 CHAS. A. BLAKE. 



Of the habits of this genus very little seems to he known, although 

 M. Drcwsen of Copenhagen, gives an accoixnt (^,/otir. Ent. Soc. Stettin, 

 1847, p. 21*0) of having obtained as many as seventy-six (S 9 ) spe- 

 cimens of M. Europaea from a single nest of a Bomhm, and of finding 

 the larva) of the Miifilla in the cells closed as usual by the full fed 

 grub of the bee ; this certainly indicates that the genus is parasitic. 



The species of the genus Mutilla, known to inhabit North America 

 are very numerous as will be seen below, but upon a more extended 

 knowledge of their economy, a number now considered distinct, will 

 doubtless prove to be sexes of one and the same species. In the synop- 

 tical table given below, I have found it necessary, in consequence of 

 the general great dissimilarity between the sexes, to separate the males 

 from the females, being able thereby to characterize the species with 

 more clearness than I could otherwise have done. 



In the genus Aijama the ocelli are unusually prominent ; the e3'es 

 very large, round, convex, smooth and polished 5 the body uuicolorous 

 — honey-yellow or castaneous — smooth and shining, with long rather 

 sparse pubescence ; the wings hyaline, rarely having dark spots or 

 bauds, and never uniformly fuliginous; and the abdomen generally 

 more or less petiolated. The female appears to be unknown. 



The exotic genus Apterogyna is remarkable for the two anterior 

 segments of abdomen being constricted and nodose, and for the great 

 length of the male antennge, which are nearly as long as the body. 



In the genus Mtjrmosa the head is subglobose; the eyes small and 

 round ; the thorax of the female longitudinally quadrangular, with the 

 anterior angles rounded, and the metathorax truncate ; the thorax of 

 the male ovate, the prothorax transverse and curving posteriorly to- 

 ward the tegulae but not reaching them ; the anterior wings have one 

 marginal and /b«r submarginal cells, the second triangular, the third 

 quadrate and the fourth extending to apex of the wing. The disparity 

 betweea the sexes is said to be great. Only one species is known to 

 inhabit North America, and while specimens of the male sex are by no 

 means rare, the female appears to be unknown. 



In the genus Methoca the ocelli are said to be distinct in both sexes; 

 the head subglobose in the female, transverse in the male; eyes ovate; 

 thorax elongate and doubly strangulated, or trinodose, in female, and 

 oblong and continuous in male; the legs of the female long and 

 slender, coxre very robust, femora subclavate, tarsi longer than tibiie ; 

 the abdomen ovato-conical in the female, attached to the thorax by a 

 short petiole, linear in male, the segments subcrenate, the apex pro- 



