748 On Aquatic Carnivorous Coleoptera or Dytiscide. 
1170. Cybister ponticus, n. sp.—Ovalis, latus, posterius conspicue latior, supra 
olivaceus, capite anterius prothoraceque lateribus testaceis, elytris vitta laterali, tere 
ad apicem producta sed ibidem parum discreta, testacea; corpore 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 may prove to be only a local race of Dytiscus roeselii; 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 epipleurz of 
the elytra are rather broader, but the sexual flattening is scarcely so conspicuous as 
in Dytiscus reeseli. 
I am not acquainted with Cybister jordanis, Reiche (vide No. 1279), which is said 
scarcely to differ from Dytiscus reselii, except by the female being quite smooth. I 
have seen from Northern Persia, two females which may be perhaps 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 epipleurze 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 
reeselii 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. 45.—Robustus, 
supra sab 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, prosterni 
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. 192 m.m. 
This species is closely allied to Dytiscus roeselii, 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 epipleuree 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. 
