664 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



wholly obliterated in that species, seems to be absent in genitalis; at 

 least it is not represented in the material studied. The surface of the 

 fastigium of the vertex between the fastigial tubercles is almost in- 

 variably blackish in hilohatus, while 

 in the present species it is con- 

 colorous with the rest of the vertex. 

 Length, pronotum, male, 3 mm.; 

 female, 3.5 mm.; posterior femora, 

 male, 8 mm.; female, 8.5 mm.; ovi- 

 positor, 5 mm.; width, pronotum 

 posteriorly, male and female, 4 mm. ; 

 hind femora at widest part, male 

 and female, 2.25 mm. 



Holotype. — Male, Los Angeles 

 Fig. 8.-GAMMAROTETTIX GENITALIS. suBGEN- Couutv, Calif omia, Juiy ; allotype, 



ITAL PLATE OF THE FEMALE TYPE. " ^ -T ^ 



female, same locality, June. Holo- 

 type and allotype in United States National Museum. Catalogue 

 No. 19407. These specimens are listed by Scudder ^ as G. hilohatus, 

 and the specimens recorded at the same time from San Diego, Cali- 

 fornia, will very likely be found to belong to this new species. 



GENUS CEUTHOPHILUS Scudder. 



CeuthophiliLS Scudder, Can. Nat., vol. 7, 1862, p. 284; Proe. Amer. Acad. Arts 



Sci., vol. 30, 1894, p. 23. 

 Machamala Walker, Cat. Derm. Salt. Brit. Mus., vol. 2, 1869, p. 209. — Kirby, 



Syn. Cat. Orth., vol. 2, 1906, p. 130. 



This, the dominant genus of the group, contains a large number of 

 species as now considered, though there is very likely some synonymy 

 among them. It is difficult to distinguish nymphs from adults and 

 this will probably prove to be the cause of some duplication of specific 

 names when the members of the genus are better known. In fact, 

 this is already proven by the reference, on a later page of the present 

 paper, of CeuthopMlus Tienshawi Scudder to the synonymy under 

 Pristoceutliopliilus celatus of the same author. 



The more important differentiating characters of the species of this 

 genus pertain mostly to the male sex, and these sometimes differ in 

 immature and adult individuals. Thus the curved hind tibiae of the 

 adult of some species are straight in immature specimens. Variation 

 in the more available synoptic characters also contributes to the 

 difficulties of a satisfactory classification. 



No attempt is made in the present paper to construct a key to the 

 species of this genus. The only comprehensive key published is that 

 by Scudder,^ and that is quite inadequate for the separation of the 



1 Proc. Amer. Acad. Arts Sci., vol. 30, 1894, p. 111. 

 "Idem, p. 23. 



