704 PROCEEDINGS OF THE NATIONAL MVSEUM. vol.xxi. 



Genus GOMPHODESMUS Cook. 

 Gomphodeamus Cook, Proc. U. S. Nat. Mns., 1895, XVIII, p. 83. 



Body larg^e, nearly six times as long as broad, taperiug sliglitly 

 cephalad, scarcely so caudad near the end; dorsum strongly convex, 

 the carin.e decurved in the direction of the dorsal arch. 



Antennse flliform, second joint longest, four following subequal. 



First segment scarcely more than twice as broad as long 5 anterior mar- 

 gin subtransverse, the posterior laterally carried around to meet it at a 

 small angle produced below the level of the other cariniB. 



Segments dorsally polished and shining. 



Lateral carinse about one-fourth as wide as the body cavity, inserted 

 at about the middle of the sides; lateral margins with a rather broad 

 distinct callus extending along the anterior and posterior edges of the 

 carinaj as a narrow distinct margin; on anterior segments the marginal 

 callus is broad but distinct; on the first segment the callus occupies 

 the entire lateral corner; posterior corners of cariiue produced increas- 

 ingly caudad from about the seventh, though only segments 15 to 18 

 have the corners much exceeding the posterior inaigin of the segment. 



Repuguatorial i)ores 13, located in large depressions, as in Astro- 

 desmiis. 



Preanal scale semicircular, apiculate, the setigerous tubercles more 

 remote than in the other large genera, very large, papilliform and 

 greatly exceeding the apex. 



Sterna without distinct transverse ridges, somewhat excavate in the 

 middle in front and with a small subconic prominence or very short 

 ridge at the base of each leg. 



Sternum of sixth segment of male with a nearly square, strongly 

 apiculate process between the bases of the anterior pair of legs. 



Sternum of fifteenth and sixteenth segments of male unmodified. 



Legs of malcfs distinctly crassate, dorsal face of second joint infiated, 

 especially in the anterior; legs 1 to 5 of male with a small fleshy sole at 

 apex, the claw distinctly reduced. 



Coxa^ of second male legs produced ventrad into a blunt pro- 

 tuberance. 



Male genitalia constructed as in Astrodesnius and Aulodesmus, but 

 with the node constricted at base, the flagellum broad and comi)ressed 

 at base, rather robust throughout and twice bidentate distad; it 

 makes a single subcircular curve, crossing and lying against its 

 fellow. 



Females with coxfe of second legs produced ventrad into a small 

 conic spine similarly situated to that of the male; laterally above the 

 insertion of the second joint the coxfe are expanded and bear two 

 rounded flattened processes; the second legs are deeply inserted, and 

 on each side of their bases is a large, round, deep cavity; the sternum 

 of the third segment is strongly produced ventrad into a thin plate, 

 broadly and deej)ly emarginate medianly. 



