Casey — A Revision of the American Paederini. 31 



forming a coarse and cleft-like stria extending to the extreme 

 base of the head, and more densely pubescent or setulose third 

 palpal joint, are characters which isolate this genus com- 

 pletely, and it is without any very close allies known to me. 

 The general habitus of Monocrypia is however not unlike that 

 of several of our common forms of Hesperobium. The gen- 

 eric diagnosis is taken from the Japanese Cryptobium apica- 

 tura and pectorale , of Sharp. 



Gastrolobiuni n. gen. 



This is by far the most extensive and widely distributed 

 genus of the American Cryptobia and includes some of the 

 largest species. It is abundantly represented in temperate 

 and tropical North and South America but has not yet 

 occurred in the true Pacific coast fauna of North America, 

 a significant fact when comparing the American and Asiatic 

 types of the subtribe. The elytral punctures generally have 

 but feeble indication of serial order, but in some cases, such as 

 lugubre, the series are almost perfectly regular, constituting 

 one of the most conspicuous features. The basal joint of the 

 antennae is only moderately long when compared with other 

 genera of the subtribe, being greatly surpassed in length by 

 Hesperobium and, to a still greater degree, by Lissobiops in 

 that respect. The male sexual characters are more elaborate 

 than perhaps anywhere else in the Paederini, and the lobation 

 of the third ventral segment is a character distinctive of, if 

 not peculiar to, this genus. In at least one Amazonian species 

 this singular lobe is strongly bilobed and there are doubtless 

 many other remarkable modifications. The hind trochanters 

 in the male of another species brought home from Brazil by 

 Mr. H. H. Smith, are greatly prolonged and spiculiform, but 

 I have remarked no such sexual character among our species. 

 The lobe of the third ventral* is not constant in size but 



* This is described as the fourth segment by Dr. Horn in his revision of 

 Cryptobium (Tr. Am. Ent. Soc, XII), he having mistaken the elevated basal 

 margin of the first segment for a basal segment partially concealed by the 

 coxae, and all the figures of the plates accompanying that paper are erro- 

 neously drawn in this respect. As illustrating the true structure of the 



