oSS On Aquatic Carnivorou.s Coleoptcva or Dyliscidce. 



rather broad and simple. Tlie species includes numerous forms or varieties, but 

 the material before me does not justify me in considering them as distinct species. 

 The female has sometimes the greater part of the elytra and the thorax at the 

 sides covered with very fine anastomosing strife, which in other specimens arc 

 quite wanting, and various intermediate gradations occur. The size also varies a 

 good deal, as does also the colour, the largest form found in Central A merica and 

 Mexico (C. signatus, Sharp) having the red marks of the elytra pale and distinct. 

 The scratches on the thorax also vary somewhat in number and depth: and the stria> 

 of the elytra ure also variable in depth. I have considered as the type of the species 

 the form occuring in the Antilles, which was the one to which Fabricius gave the 

 name Dytiscus posticatus. 



Antilles, (Cuba, Guadelopc) ; Mexico; Central America; Cayenne; Brazil. 63G. 



876. Copelatus terminalis, n. sp. — Ovalis, latus, depressus, nitidus, subtus rufo- 

 testaceus, supra nigrican.s, capite, prothorace ad latera,elytris basi et apice(s£Bpiusque 

 macula laterali),antennis pedibusquetestaceis; prothorace strigulisbrevibus impressis ; 

 elytris striis decern subtilibus, alternis posterius abbrcviatis, aliaque marginali 

 brevissima. Lonfj. Gi, lat. 31 m.m. 



The male has the front and middle tarsi distinctly dilated, and the front tibice 

 broad and simple; it has the thorax scattered over with short linear punctures, 

 which become obsolete towards the sides, in the female these punctures are more 

 elongate, and are more developed near the side than they are on the middle. 



The striaj of the wing-cases are quite regular at the base, the first is a little more 

 distant from the suture than it is from the second, and is carried on nearer to the 

 tipex than any of the others are, the alternate ones are distinctly shorter than the 

 others, and nearly of one length ; the submarginal stria is very short, and placed 

 ■nearly entirely behind the middle. 



The distinct yellow marks on the elytra are variable, besides the spot near the 

 side (on the 8th and 9th interstices) there is generally another on the .5th interstice, 

 and this may become elongate and connected with the basal band. 



The species is very similar to a variety of Dytiscus posticatus, which resembles 

 it in markings, (C. signatus. Sharp), but C. terminalis is broader, the strife of the 

 elytra are finer, and the alternate ones, (especifdly thii second), arc less abbreviate 

 behind. 



Central America, (S. Geroniino, and El Jicaro, Vera Paz, Guatemala; Champion). 1102. 



877. Copelatus depressus, n. sp. — Oblongo-ovalis, paruni latus, depressus, subtus 

 rufo-testaceus, abdomine fuscescetite, supra fusco-piceus, caj^ite, prothorace late ad 

 latera, elytris basi apiceque testaceis, antennis pedibusque testaceis ; elytris striis 



