74S On Aquatic Carnivorous Coleopteni or DytiscidcB. 



1170. Cybister ponticus, n. sp. — Ovalis, latus, posterius conspicue latior, supra 

 olivaceus, capite anterius prothoraceque lateribus testaceis, elytris vitta lateral!, fere 

 ad apicem producta sed ibidem parum discreta, testacea; corpora subtus testaceo, 

 tarsis intermediis, tibiis tarsisque posterioribus piceis; femoribus posterioribus angulo 

 externo acuto. Long. 37, lat. 21 m.m. 



I have seen only a single individual of this form, and although it is quite without 

 sexual sculpture, I think it ruay prove to be only a local race of Dytiscus rceselii ; it is 

 however considerably larger, and has the hind legs thicker, and the marginal band of 

 the elytra remains broader and more distinct at the extremity ; the epipleurae of 

 the elytra are rather broader, but the sexual flattening is scarcely so conspicuous as 

 ill Dytiscus rceselii. 



I am not acquainted with Cybister jordanis, Reiche {vide No. 1279), which is said 

 scarcely to differ from Dytiscus rceselii, except by the female being quite smooth. I 

 have seen from Northern Persia, two females which may be pei'haps but little different 

 from this Jordan form ; they have the upper surface quite free from sculpture, and 

 differ from Cybister ponticus in being considerably smaller, and of narrower and 

 more parallel form, the swimming legs are more slender and the sexual flattening 

 of the epipleurse is less : these two specimens were found by the Marquis Doria in 

 Northern Persia in 1862-3. Whether these forms with smooth females, viz., lusit- 

 anicus, jordanis, ponticus, are really closely allied but distinct species, or are only 

 races occurring at the extreme geographical limits of the distribution of Dytiscus 

 rceselii is a very difficult question which I am quite unable to answer. 



Mesopotamia, (Millingen). 1048. 



1171. Cybister japonicus, Sharp, Tr. Ent. Soc. Lond. 1873, p. ib. — Robustus, 

 supra sat convexus, ovalis, posterius latior, supra olivaceo-niger, capite anterius 

 prothoraceque lateribus testaceis, elytris vitta laterali sat lata, apicem fere attingente 

 sed ibidem parum discreta, testacea; corpore subtus variegato, testaceo, prosteriii 

 processu pectoreque in medio olivaceo-nigris, abdominis coxarumque posticarum 

 suturis nigris ; pedibus testaceis, tarsis intermediis, tibiis tarsisque posterioribus 

 piceis, femoribus posterioribus versus basin plus minusve picescentibus ; femoribus 

 posterioribus angulo externo acuto. Long. 35, lat. 19? m.m. 



This species is closely allied to Dytiscus rceselii, and possesses in each sex the 

 same sexual characters as that species, but it is considerably larger, and has the 

 yellow band on the sides of the elytra broader, and less distinctly separated from 

 the lateral margin, and has the undersurface very distinctly variegated : the female 

 has the flattened portion of the epipleurse broader : it is also rather different in 

 form, being less narrowed in front, and it has the hinder tarsi longer. 



Japan, Formosa, Mantchuria, China, (Shanghai). 1049. 



