484 PROCEEDINGS OF THE ACADEMY OF [1893. 



NOTOGONIA Costa. 



Larrada Sin., 1. c. p. 274. 1856. 



Notoffonia Costa, Ann. Mus. Zool. Univ. Napoli (Ann. IV), p. 80 et 82- 1867. 



Lai ra Patton, Proc. Boston Soc. Nat. History, XX, p. 385. 1880. 



Head a little broader than the thorax ; mandibles emarginate on 

 outer edge and with a tooth or inner edge between the middle and the 

 bate, their apex simple ; antenna? more slender than in Larra ; eyes 

 converging to the vertex, the convergence greater in the $ than in 

 the 9 and differing in the various species, generally stronger than the 

 Larra, to which this genus agrees in the ledge-like swellings of the 

 front and the disposition of the ocelli ; the collar is smaller than in 

 Larra ami moreover differs from it by being depressed beneath the 

 dorsulum; wings as in the preceding genus ; the legs are proportion- 

 ately longer than in Larra, stoutly armed ; middle coxae widely sep- 

 arated from each other ; middle tibia? one-spurred ; anterior tibia?, 

 with exception of their end spurs and a spine not far from the middle 

 of inner side, unarmed ; the comb of fore tarsi is formed of only a 

 moderate number of spines, which at the most are not particularly 

 long and only in a few species reach an extraordinary development ; 

 the posterior tibia show, though not ahvays, but in almost all the spe- 

 cies known, two sharp) longitudinal keels*, which are spinose. The 

 claws are very long, in rare cases with a tooth not far from the base 

 of inner edge ; pulvilli small; metathorax as long or longer than the 

 dorsulum; abdomen not polished as in Larra; second ventral seg- 

 ment in the middle near the base with a convexity, the size and form 

 of which differs considerably ; commonly the segment appears almost 

 keeled ; to each side of the convexity there is a more or less expanded 

 oval, flat impression of feebler color; these impressions are always 

 present if the convexity is distinct and give the hind trochanters a 

 freer motion. The males do not show these relations of the third 

 ventral plate or only very slightly ; last dorsal segment with a py- 

 gidial area, formed in the 9 as m Larra and covered with a more or 

 less fine, generally hoar-frost-like pubescence, which easily wears off 

 and in old individuals is not at all perceptible ; at the apex of the py- 

 gidial area there are some stiff little bristles; the last dorsal segment of 

 the 9 is trapezoidal and often considerably convex and at the apex 

 margined outwardly. 



3 Seemingly not evident in our three species. 



