On Aquatic Carnivorous Coleoptera or DytiscidcE, 575 



prothorax is finely punctulate, witli a few fine, very short scratches near the sides. 

 There are two forms of tlie female, in one of them the thorax and the whole of the 

 elytra, except the apices, are densely covered with fine anastomosing striae ; while 

 the second form only differs from the male by the simple tarsi, and by the fact 

 that the fine short scratches on the sides of the thorax have a rather sfreater 

 extension towards the middle. The species is exti'emely closely allied to Copelatus 

 neglectus (No. 841), but is less elongate in shape, has the scratches of the thorax 

 in the second form of the female much less developed ; and has the elytral striae 

 finer, with the alternate ones more abbreviate behind, so that indeed the sixth and 

 especially the eighth are more or less reduced ; this character is however variable, 

 for in some individuals, the sixth and eighth striie are nearly entirely absent, while 

 in others they arc but little shorter than the fourth. I have seen of the male only 

 a single very mutilated example. 



South America, (Pampas, Germain). G42. 



841. Copelatus neglectus, n. sp. — Oblongo-ovalis, angustulus, elongatus, nigricans, 

 capite, prothoracis lateribus elytrorumque basi et apice rufis, antennis pedibusque 

 testaceis ; prothorace in mare fare Isevigato, versus latera indistincte punctato, in 

 femina dense striguloso ; elytris striis decem sat subtilibus, alternis brevioribus. 

 Long. 52, lat. 2-4 ra.m. 



The male has the front and middle tarsi rather broadly dilated, and the front 

 tibise nearly simple. There are two forms of the female, in one of them the thorax 

 and the whole of the elytra, except the apices, are densely covered with fine 

 anastomosing sti-ios, while in the second form there is no trace of such a sculpture 

 to be detected, in this latter form the scratches on the thorax are not so dense and 

 distinct as in the first. 



South America. (Venezuela, Cumana). 641. 



842. Copelatus concolor, n. sp. — Ovalis, sub-depressus, sat latus, nitidus, castaneo- 

 testaceus ; prothoi-ace la3vigato ; elytris striis decem subtilibus, alternis brevioribus. 

 Long. 6, lat 3 m.m. 



In the male the front and middle tarsi are moderately dilated ; the front tibise 

 are stout and simple. In the female tliere are some veiy fine scratches at the sides 

 of the thorax, and some more distinct ones on the external parts of the elytra a 

 little in front of the middle ; in one of the females these scratches on the elytra are 

 very much diminished. 



South America, (Amazonia, Tebas, Rio Purus, 25. 10. 1.S7-1, L>r. Trail). GIO. 



