244 



COLEOPTERA OF NORTH AMERICA. 



indefinite. I shall therefore give simply a synoptic table of our 

 genera without attempting further division. 



Front entirely corneous ; Stenochidus.* 



Front with the anterior margin subcoriaceous ; 



Mandibles emarginate at tip ; sixth ventral segment invisible ; 

 Anterior coxa? separated by prosternum; 



Tarsi with distinct lobes. Allecula. 



Tarsi with obsolete lobes ; 



Last joint of maxillary palpi longer than wide. Cistela. 



Last joint of maxillary palpi transverse. Stigmatoma. 



Anterior coxa? contiguous, cavities confluent. Mycetochaees. 



Mandibles emarginate at tip ; sixth ventral segment visible (tarsi not 



lobed) ; 



Second and third joints of antenna? equal, very small. Chkomatia. 



Third joint of antenna? longer than the second. Capnochroa. 



Mandibles with the tip entire. Androchieus. 



To Stenochidus belong Stenochia gracilis Lee. and Prionychus 

 cyanescens Lee., from California. The species of Allecula and 

 Cistela are numerous, and the majority are undescribed; Cistela 

 is found on both sides of the continent. Of Stigmatoma I have 

 three species ; all are shining black with red humeral spots. The 

 only one described is Cistela fraterna Say. Of Mycetochares I 

 have four species, of which M. binotata Say is the only one de- 

 scribed. Chromatia is founded upon Cistela amoena Say, a 

 species with strongly serrate antennae, which differs from Cistela 

 not only by the third joint of the antennas being very small, but 

 by the sixth ventral segment being prominent and deeply exca- 

 vated in the male. Capnochroa is established on Cistela fuligi- 

 nosa Mels., a large species which, with all the other characters 

 of Cistela, differs by the sixth ventral segment being visible in 

 both sexes, and in the male very deeply excavated, so as to form 

 two flattened, curved processes. The eyes are large. 



The type of Androchirus is Cistela fuscipes Mels., found in 

 the Middle States ; it is a large species with yellow legs, and' the 



* This genus has the thorax narrower than the elytra, and thus approaches 

 in form the Australian genus Atractus. The mandibles are truncate ; at the 

 base of the labrum is an obsolete clypeus ; the last joint of the much elon- 

 gated maxillary palpi is large and securiform : the anterior coxa? are small 

 and globular ; the intercoxal process of the abdomen is narrow ; the third 

 and fourth joints of the front and middle tarsi, but only the third joint of 

 the hind tarsi, are lobed beneath. This genus, by the form of the front 

 and of the anterior coxa?, indicates a separate group ; the species are of a 

 dark, submetallic color, and entirely glabrous. 



