On Aquatic Carnivorous Coleoptera or Dytiscidce. 325 



189. Hydrovatus caraibus, n. sp. — Brevior, convexus, nitidus, ferrugineus, 

 elytris pectoreque fuscis, illis basi crebre fortiter, versus apicem obsolete 

 parcissime punctatis. Long. 2?, lat. If m.m. 



This species is convex, and not very broad ; the front of the head is very dis- 

 tinctly margined, the surface of the head impunctate. The thorax is at the base 

 closely and rather coarsely punctured, elsewhere the punctures are indistinct. The 

 elytra at the base are deeply and closely punctured, but the punctures become finer 

 and more scanty behind so as to be altogether wanting at the apex ; they are dark 

 in colour, without spots, but the apex is pale. The hind coxge are coarsely punc- 

 tured. 



The individual described is no doubt a female as it has the tarsi quite small ; the 

 wing-cases are, however, shining. It is larger than H. brevipes (No. 1 87), and 

 distinguished from it by the closer punctuation of the base of the wing-cases, which 

 also in the female of H. brevipes are dull. 



Guadaloupe. 1177. 



190. Hydrovatus aristidis, Lep. Ann. Soc. Fr., 1879, p. Ixxxii. — Crebre punctatus, 

 brevissimus, ferrugineus, elytris thoraceque infuscatis, hoc medio late rufo, illis 

 obscure rufo-signatis ; prosterno medio ti'ansverso. Long. 2-2-, lat. if m.m. 



Mas, antennis deformibus, articulis intermediis dilatatis, 8-10 simplicibus, 11° 

 iterum dilatato. 



Extremely similar at first sight to Hyphydrus cuspidatus (No. ISO), but with 

 the punctuation of the upper surface rather closer and coarser ; the clypeus is 

 margined, but the margin in the middle is more depressed than in H. cuspidatus, 

 and therefore not so distinct. The front and middle tarsi are a good deal longer 

 than in H. cuspidatus, and the process of the prosternum is transverse instead of 

 triangular, the front part being truncate instead of acuminate : the punctuation of 

 the coxae is less close and rather coarser. 



I have only seen a single specimen of this species, which I have no doubt is a 

 male : the structure of its antennae is very remarkable : the first and second joints 

 are simple, the third is broader than second, the fourth is broader than the third, 

 very short, and slightly produced on the inner side, the fifth is extremely short and 

 very broad, being much produced on the inner side, the sixth is very transverse, 

 being just of the width of the fifth, but rather longer than it, the seventh is very 

 laro-e and is dilated both on the outer and inner sides, eight to ten are simple and 

 rather elongate, while the apical joint is again dilated, being about as long as, but 

 not so broad as, the seventh. 



Egypt. 5. ^^^ 



