THE PREDA.CEOUS DIVING BEETLES. 



223 



XI. Matus Aube. 1838. 

 Here belongs one medium-sized species having the head very 

 broad ; thorax margined ; prosternum deeply silicate ; claws of hjnd 

 tarsi unequal, the outer one being nearly twice as long as inner. 



431 (1404). Matus bicarinatus Say, Trans. Amer. Phil. Soc, II, 1823, 98; 



ibid. II, 512. 



Elongate-oval, slightly convex. Uniform brownish-red, shining; an- 

 tennae paler. Thorax rounded at sides, front angles acute. Elytra with 

 two or three rows of faint dorsal punctures. Length 8-9 mm. 



Lake, Marshall, Wells, Marion and A r igo counties; frequent. 

 Hibernates. March 14-Deeember 20. Readily known by the elon- 

 gate form and peculiar color. 



XII. Coptotomus Say. 1834. (Gr., ''cut + joint.'') 

 Medium-sized oval species having the terminal joint of the palpi 

 somewhat compressed and notched at tip ; prosternum with an ele- 

 vated carina; last joint of hind tarsi equal to fourth; claws equal, 

 pressed together and apparently single. One 

 species occurs in the State. 



432 (1396). Coptotomus inteerogatus Fab., Syst. 



Eleut, I, 1801, 267. 

 Elongate-oval, subconvex. Head, thorax and un- 

 der parts reddish-brown; vertex black; thorax 

 black at base and apex; elytra pitch-brown, with 

 numerous very small pale markings, a short stripe 

 near the scutellum and an irregular marginal stripe, 

 yellowish. Female with basal portion of elytra 

 less shining than in male and marked with short, 

 dense indistinct striae. Length 7 mm. (Fig. 111a.) 



Throughout the State; frequent. March 

 IG-October 28. Probably hibernates. Taken 

 at electric light in June. Fi s- ( A fter Sharp.) 



XIII. Copelatus Er. 1832. (Gr., "oar or leg + wide.") 

 Rather small beetles having the claws equal in both sexes ; pro- 

 sternum with an acute carina in front ; hind femora not ciliate at 

 apex. The males have the fore and middle tarsi dilated and fur- 

 nished with small eqnal disks. One species occurs in Indiana. 



433 (1402). Copelatus glyphicus Say, Trans. Amer. Phil. Soc, II, 1S23, 



99 ; ibid. II, 512. 



Oblong-ovate, rather narrow, subdepressed. Dark reddish-brown or 

 piceous ; antennae and legs paler. Thorax almost smooth. Elytra each with 

 ten deeply impressed stria?, reaching almost to apex. Length 5-6 mm. 



Throughout the State ; scarce. April 4-October 21. 

 [15—23402] 



