744 On Aquatic Curnivorous Coleoptera or Dytiscida. 
The male has the front tarsi large, attaining 4 m.m. in the transverse direction ; 
the two basal joints of the intermediate feet are entirely clothed beneath with short 
sexual pubescence. The female has a highly developed sexual sculpture, the thorax 
being entirely covered with short irregular scratches, and the elytra having elongate 
scratches on all but about the hinder one-sixth of their surface, the scratches how- 
ever do not quite attain the suture except at the base; the epipleure are flattened 
and obliquely horizontal, the torsion commencing near the base and ceasing gradually 
about the hind margin of the second ventral segment. 
The variegation of the ventral segments is in this species indefinite, the first and 
second ones are largely pale towards the sides, while the yellow lateral colour on 
the following segments assumes more the form of indefinite yellow spots. 
The locality of this species is open to some little doubt. I have a pair from 
W. W. Saunders’ collection, labelled “ bengalensis, Aubé,” but with no locality ; 
another specimen stood in Dejean’s collection labelled “Dytiscus javanus, mihi h. in 
Ins. Java ;” a fourth individual stood in Chevrolat’s collection as one of three in- 
dividuals under the label “Cybister limbatus, Fab. Dj. Aubé, aciculatus Olivier, India 
or. ex Mus. olivieri ;’ the other two individuals were females of Dytiscus limbatus. 
India (2) (Java?). 1095. 
1165. Cybister cognatus, n. sp.—Major, ovalis, supra olivaceus, capite anterius 
prothoraceque ad latera testaceis, elytris vitta intramarginali, versus apicem argute 
hamato-dilatata, testacea ; corpore subtus variegato, prosterno pectoreque in medio 
nigricantibus, abdomine in medio late fuscescente, lateribus late vageque testaceis ; 
pedibus anterioribus et intermediis testaceis, his tarsis piceis, pedibus posterioribus 
nigricantibus femoribus ad apicem rufis. Long. 35, lat. 193 m.m. 
The male tarsi are only moderately large attaining about 3 m.m. in the transverse 
direction; on the intermediate feet the patches of short sexual pubescence on the 
first and second joints seem to be a good deal smaller than in the allies, the one on 
the second joint being quite narrow. 
The sexual sculpture of the female is but moderately developed, being obsolete 
on the thorax, and on the elytra extending only about half way to the apex, and 
being broadly absent along the sutural region ; the epipleure are only slightly and 
obscurely flattened, and the torsion extends but for a small distance in the longi- 
tudinal direction. 
This species bears an extreme resemblance on the upper side to Dytiscus limbatus 
(No. 1157) but is readily distinguished by the colour of the undersurface : it is allied 
to the preceding species, but is distinguished readily enough, the form being less 
narrow in front, and less convex, the dark colour on the undersurface is less exten- 
sive, and the male tarsi are different, and the sexual distinctions in the female much 
feebler. The two species differ moreover remarkably from all their allies by the 
highly developed and remarkable structure of the cedeagus. 
