On Aquatic Carnivorous Coleoptera or Dytiscidce. 659 



turisque disjunctis, testaceis ; pedibus posterioi'ibus robustis, tarsorum raarginibus 

 posterioribus sat longe ciliatis. Long. Hi, lat. 8f m.m. 



This species is very similar to H. jucundus, but the yellow marks on the elytra 

 are isolated from one another and less extensive, and the thorax is a little different, 

 it being rather shorter and more curved at the sides near the posterior angles which 

 are more rounded, it is more punctured near the sides and less evenly convex 

 transversely ; so that in the form of the thorax the species makes a distinct approach 

 to the peculiar Prodaticus pictus (No. 1005). The sexual characters both of the 

 male and female seem to he quite the same as in H. jucundus, except that the 

 female has no distinct impressions on the lateral part of the thorax, the surface 

 there being, however, uneven and obscurely corrugated. 



Sinai, Egypt, Nubia. 1021. 



1026. Hydaticus jucundus, Reiche, M.C.^Ovalis, sat latus, nitidus, rufo-testaceus, 

 vertice prothoraceque basi in medio elytrisque nigi-is, his margine externo .signa- 

 turisque irregularibus plus minusve trausversim dispositis testaceis ; pedibus 

 posterioribus robustis, tarsorum marginibus posterioribus sat longe ciliatis. Long. 

 14i, lat. n m.iu. 



The male front tarsi are highly developed, the fringing hairs being very long, and 

 the palettes large, the basal ones being particularly large ; the middle tarsi are 

 somewhat broadly dilated : the female has some coarse irregular impressions on the 

 lateral parts of the thorax ; in this sex there are some fine scattered punctures on 

 the wing-cases, which are almost entirely absent in the male. The male has an im- 

 pression at the apex of the last ventral segment, causing the hind margin to be 

 depressed in the middle and to appear emarginate : the female has a longitudinal 

 impression which reaches just as far as, but does not depass, the hind margin. 



This species seems to be somewhat variable in size and in the yellow marks of 

 the elytra ; these marks especially near the sides and extremity are dotted with 

 black. 



Abyssinia. 1020. 



1027. Hydaticus dregei, Aubd, M.C. — Ovalis, parum latus et convexus, laevigatus, 

 nitidissimus, rufo-testaceus, vertice, prothorace basi in medio elytrisque nigris, his 

 signaturis irregularibus margineque externo testaceis; pedibus posterioribus sat 

 gracilibus, tarsorum marginibus posterioribus baud longe ciliatis. Long. 13i, 

 lat. 71 m.m. 



On the front tarsi of the male the fringing hairs are very highly developed and 

 the palettes are of very unequal sizes, the basal ones, especially the posterior one, 

 being of large size; the middle tarsi are only moderately dilated: the female has 



TRAN3. BOV. DUB. SOC. N.S., VOL. II. * Q 



