TI1K I'UKI) U'I'X)US 1MVJNC BKKTI.KS. '_>:!."> 



rows of disks on under side. The elytra of female are either smooth 

 or rough, with minute tubercles. Two species are known from In- 

 diana. 



4(iO (14!>8). (JKAPIIODEKES UBEKUs Say, Jouni. 1'liil. Acad. Nat. Sci., V, 

 1S25. 1UO; ibid. II. 271. 



Slightly obovate, subdepressed. Head and thorax dull reddish-yellow. 

 the latter sometimes piceous at base; elytra blackish-brown, with numerous 

 fine yellow vermiculate marks, these sometimes forming ;i yellowish mar- 

 gin; under surface reddish-brown, the legs paler. Elytra each with two 

 rows of indistinct dorsal punctures. Length 11.5-12 mm. 



Putnam and Lawrence counties; frequent in woodland ponds. 

 August 7-August 12. 



461 (1409). GRAPIIODERES FASCICOLLIS Harr., N. Eng. Far.. VII, 1S2S. ir.<5. 



Broadly ovate, subconvex. Head with occiput and an M-like mark 

 black; thorax dull yellow with a rather broad black bar on front and hind 

 margins; elytra blackish, thickly marked with dull yellow dots, the mar- 

 gins and a very narrow sutural line yellow; under surface dull brownish- 

 yellow. Length 13.5-14.5 mm. 



Lake and Marion counties; scarce. March 23-May 27. This 

 species is said by Sharp to be distinguished from the European G. 

 cinercus Linn, by the male having fewer disks on the front and 

 middle tarsi. In one male from Pine, Indiana, the middle tarsi are 

 not at all dilated. 



Tribe IV. CV1USTRINI. 



This tribe is represented in the fTnited States by a small number 

 of large species belonging to the single genus Ci/l>islcr. They have 

 the spiracles very small; hind legs broad and powerful; their tibia 1 

 short and broad, witli the lower one of the two apical spurs dilated; 

 hind claws very unequal, the inner being obsolete or wanting in our 

 species. The front tarsi of the males have joints 1-3 dilated into a 

 large circular disk bearing four rows of equal-sized cupules. In the 

 hollows behind the hind coxa? of the males are four or five deep 

 ridges which, when rubbed by a ridge on the under side of the fe- 

 mur, form a stridulating organ. 



XXIV. CYBISTER Esch. 1883. (Gr., "a tumbler or diver.") 



This genus is considered as representing the highest and most 

 completely developed form, of Dytiscid-e. One of the five species 

 ]mown from the United States occurs in Indiana. 



