• 



506 TRANSACTIONS OF THE 



Family III. HYDROCANTHARI. 

 DYTISCUS Lin. Latr. 



Antennae longer than the head, setaceous ; scutel distinct ; 

 three basal joints of the anterior tarsi, in the male, dilated, 

 patelliform ; palpi filiform. 



1. D. FiMBRioLATUS. — Attenuated before, blackish -green 

 above; thorax and elytra yellowish on the outer margin, the 

 latter with three series of punctures. [92] 



Dytiscus Jimbriolatus Melsh. Catal. 



Length one inch and one-fifth. 



Body dark green, beneath piceous-black, impunctured, very 

 distinctly widest behind and narrowed before ; head smooth, with 

 a slightly impressed spot on each side of the front; nasus and 

 labrum yellowish, the latter with an impressed transverse punc- 

 ture each side, the former blackish at base above ; trophi and 

 antennae rufous ; mandibles at tip and labium black-piceous ; 

 thorax with numerous, minute, impressed, irregular lines, an 

 anterior, abbreviated, indented, transverse line each side of the 

 dorsal one, lateral margin yellowish ; elytra with very numerous, 

 abbreviated, longitudinal, irregular, impressed, unequal lines, 

 which are obsolete near the suture, tip, and on the outer margin, 

 three series of distant punctures slightly villous, lateral one 

 indistinct, costal margin yellowish, which becomes obsoletely 

 semideltoid near the tip ; pectus and postpectus piceous-black ; 

 feet piceous ; femora and basal joints of the anterior pairs yel- 

 lowish-rufous ; venter piceous, three lateral rufous punctures on 

 each side. 



A black spot is often present on the middle of the yellow 

 thoracic margin. This species approaches exceedingly near to 

 D. limhatus of E. India ; but, according to the observations of 

 Dr. J. F. Melsheimer, it is smaller, the color is less olivaceous, 

 more of a deep green, and the form a rather longer oval. 



[A species of Cyhister, afterwards described as C. dissiniilis 

 Aube. — Lec] 



2. D. VERTiCALis. — Suboval, above blackish, with greenish re- 



[Voi. n. 



