On Aquatic Carnivorous Coleoptera or Dytiscidce. 719 



pubescence on the basal joint of the intermediate tarsi is also less obsolete. From 

 C. siamensis, it differs by its smoother surface, and by the larger male tarsi ; while 

 from C. convexus, it differs by its comparatively broader form which is more 

 narrowed in front, and by its upper surface being less convex in the transverse 

 direction, and by the male tarsi being rather larger. 



East India. 1057. 



1128. Cy bister brevis, Aub^, Tragus hrevis, M.C. — Ovalis, latus, anterius angus- 

 tatus, supra olivaceo-niger, clypeo anterius vage irregulariter testaceo, subtus niger, 

 antennis rufis extrorsum fuscescentibus, pedibus nigris rufo-variis ; capita crebre et 

 fortiter, thorace sparsim subtilius, punctato. Long. 22, lat. 12i m.m. 



The front tarsi of the male are rather small, and the band of sexual pubescence 

 on the basal joint of the intermediate tarsus is only very slightly developed; the 

 female shows no peculiar sexual sculpture. 



The peculiar punctuation of the head renders this species unmistakable ; except 

 for that character it is allied to C. siamensis, but it is smaller, has the elytra 

 smoother, and their epipleurae not so broad and flat in their posterior portion. The 

 yellow mark on the front of the clypeus consists of an angular mark on each side, 

 the two being connected together by a very short middle portion. 



Japan. 1058. 



1129. Cybister filicornis, n. sp. — Parvus, ovalis, latiusculus, anterius fortiter 

 angustatus, supra parum convexus, niger, clypeo anterius prothoracisque lateribus 

 testaceis, pedibus anterioribus et intermediis rufis, femoribus basin versus fuscis ; 

 pedibus posterioribus piceis ; antennis rufis, extrorsum fuscis, elytrorum epipleuris 

 versus apicem latis, et planatis. Long. 172, lat. 10 m.m. 



The anterior tarsi of the male are small, and the basal joint shows beneath a 

 shining space instead of the usual pubescent area ; the basal joint of the intermediate 

 tarsus shows beneath a linear band of short sexual pubescence, and there is a very 

 alight development of similar pubescence at the extreme base of the second joint : 

 the female has no sexual sculpture. 



This peculiar little species bears a great resemblance to small specimens of the 

 American Dytiscus Itevigatus (No. 1106), but the male has only one claw on the 

 hind tarsus, and the female has no trace of sexual sculpture : it cannot be mistaken 

 for any other. 



According to the few specimens before me it varies somewhat in size and colour ; 

 a variety from Portuguese Guinea, is smaller than the specimens from the Gaboon, 

 has the upper surface more olivaceous, and the yellow band on the sides of the 

 thorax broader. 



