353 



Specimens nine. Extremely like C. coUaris, Gyllenhall, and may prove 

 to be a variety of that European species, from which it differs, principally, 

 in being much darker beneath, paler above, and of rather larger size. 



C. *binotaius. Beneath blackish, ventral segments piceous at tip; head 

 and thorax ochreous, the former with two triangular spots between the eyes, 

 the latter Avith two central subquadrate spots black : each elytron with four 

 series of punctures, a pale suture and margin, the disc iiTorate with black 

 dots and tortuous lines; three longitudinal series of spots, and a broad fascia 

 behind the middle, obsolete, black. 



Length nine twentieths of an inch. 



Specimens three. It is possible that this may be the irroratus of Fab- 

 ricius. 



C. *tceniolatus. Ferruginous ; head at base and a vertical spot black ; tho- 

 rax greenish black at base and tip, the black portions dilated and confluent in 

 the middle; elyti-a greenish black, each with about eight irregular series of 

 deep punctures; external margin, interrupted basal fascia, and three narrow 

 lines pale testaceous : all beneath ferruginous. Length thirteen fortieths, 

 breadth between six and seven fortieths of an inch. 



Sufficiently distinct from C. venustus, Say, and Dytiscus interrogatus of 

 Fabrlcius. Specimens six. 



C. *discolor. Black, minutely and obsoletely granulated. Head with 

 two basal piceous spots; elytra fuscous, margin and base pale, epipleura 

 yellowish; three series of setiferous punctures, which are obsolete behind, 

 on each elytron: ventral segments at tip and feet piceous: nails alike in 

 both sexes. 



Length over three tenths of an inch. 



Specimens five. Appears to differ from all of the species described by 

 Mr. Say. 



C. *acuductus. Oblong oval, black, minutely acuducted; head before, 

 two vertical spots, lateral margins of the thorax, and humerus piceous; 

 pectus and feet ferruginous. 



Length over five twentieths of an inch. 



One individual in the collection of Mr. Oakes. Easily recognised by the 

 numerous short scratches or acuducted impressions. 



GENUS HYDROPORUS. 



H. *fascia(us. Ferruginous, body minutely punctured above, with de- 

 pressed hairs : antennje blackish at tip ; head with a dilated oblique Inden- 

 tation each side in front of the eyes, and a vertical blackish spot; thorax 

 black at tip and base ; elytra black, an abbreviated sometimes interrupted 

 fascia near the base, another trimacular behind the middle, and an apical 



OCCAS. PAPERS B. S. N. H.— I. 23 



