734 On Aquatic Carnivorous Coleoptera or Dytiscidoe. 



1147. Cybister esplanatus, Lee, Tragus explanatus, M.C. — Ovalis, convexus,. 

 parum latus, supra olivaceus, capite anterius prothoraceque ad latera testaceis, 

 elytris margine externo, (cum epipleuris) late testaceo ; subtus ferrugineus, iu medio 

 plus minusve olive?cens, pedibus quatuor anterioribus testaceis, tarsis interrnediis 

 picescentibus, pedibus posterioribus ferrugineis, tarsis magis picescentibus, femori- 

 bus angulo externo posteriore spinoso-acuto ; elytrorum epipleuris versus apicem 

 sat latis et planatis ■ Long. 27, lat, 14^ m.m. 



The male has the anterior tarsi moderately large ; the intermediate tarsi have 

 the three basal joints with long sexual hairs beneath, there is a slight development 

 on the fourth joint of sexual pubescence, and on the fifth joint the setjB have under- 

 gone a partial transformation into long sexual pubescence. The female has fine 

 sexual sculpture largely distributed over the thorax and head, but none at all on 

 the wing-cases. Both male and female have in the hollow near the articulation of 

 the swimming legs four or five short, coarse folds or ridges, these are better developed 

 in the male than in the female. 



This is a very distinct specie.? bearing a superficial resemblance to Cybister ellip- 

 ticus Lee, (No. 1120). It has a tendency to development of yellow colour along the 

 anterior and posterior margins of the thorax. 



North America. (California). 1078. 



1148. Cybister reichei, Aube, Tragus reichei, M.C. — Minor, ovalis, parum con- 

 vexus, fere angustus, nitidus, capite oHvaceo, anterius late testaceo, prothorace ad 

 latera et ad marginem anteriorem testaceo, basi in medio late olivaceo, elytris olivaceis, 

 late testaceo-cinctis ; corpore subtus testaceo, pectore in medio prosternique processu 

 obscurioribus, tarsis intermediis, tibiis tarsisque posterioribus piceo-rufis ; elytrorum 

 epipleuris versus apicem latis et planatis ; trochanteribus posterioribus apice libero, 

 spinoso-acuto. Long. 20, lat. 9| m.m. 



The male has the anterior tarsi small ; the intermediate feet with the three basal 

 joints largely furnished beneath with rather short sexual hairs, and their claws a 

 little elongate. 



The female has fine, short, distant scratches on the basal portion of the wing-case, 

 and on the thorax. 



This little species cannot be confounded with any but the following one on account 

 of the spinose posterior trochanters. The extent of the dark colour on the thorax 

 is no doubt variable ; the yellow band of the elytra does not terminate in a point 

 at the suture, but is joined distinctly to the band on the other wing-case. 



There is some doubt as to the habitat of this little known species. Aube 

 was acquainted with only two individuals, one of which was said to be from Brazil 

 the other from Senegal. I have myself seen only two individuals, a male from 

 Chevrolat's collection, labelled " Egypte, Flourens," and a female in my own collection 



