THE PKEDACEOUS DIVING BEETLES. 



419 (1375). Hydroporus diffobmis Lee, Proc. Phil. Acad. Nat. Sci., 1855, 



298. 



Elongate, obconic. Nearly uniform dark reddish-brown, glabrous; an- 

 tenna* and legs paler. Punctures of elytra uniform in size and rather coarse; 

 those of thorax much finer. Prosternal spine elevated at sides and along 

 the middle. Hind coxal lobes strongly developed. Length 5.5-6.2 mm. 



Taken only in Marion County, from woodland pond near Broad 

 Ripple; scarce. March 14. Our largest member of the genus. 



420 (1328). Hydroporus striatopunctatus Melsh., Proc. Phil. Acad. Nat. 



Sci., II, 1844, 28. 



Elongate-oval. Thorax and ground color of elytra piceous ; elytral 

 markings consisting of a sub-basal curved bar, an indistinct subapical and 

 a distinct apical spot, dull yellow. Upper surface finely and sparsely pubes- 

 cent. Elytra each divided into three subequal spaces by two smooth im- 

 punctured longitudinal lines ; the intervals between them coarsely and 

 sparsely punctured. Length 3.2 mm. 



Marshall County, near south end of Lake Maxinkuckee; rare. 



June 27. 



421 (1320). Hydroporus consimilis Lee, Agass. Lake Sup., 1850, 214. 



Oval, rather wide, slightly attenuate behind. Head 

 and thorax reddish-yellow, the latter fuscous on base 

 and apex. Elytra blackish, with three irregular red- 

 dish-brown spots; one marginal; extending from the 

 humerus back one-third the length of elytron, then 

 across nearly to suture, where it expands ; one be- 

 hind the middle and one near or at apex ; these very 

 variable in size and form. Length 4.5 mm. (Fig. 110.) 



Northern half of State ; frequent. April 4- 



OctODer 23. (After Wickham.) 



422 (1314). Hydroporus undulatus Say, Trans. Anier. Phil. Soc, II, 1823, 



102; ibid. II, 99, 515. 

 In LeConte's table this species is separated from consimilis only by the 

 broader margin of the thorax. In the specimens at hand the ground color 

 is somewhat paler and the reddish-brown marks of the elytra are smaller 

 and more indistinct than in consimilis. Elytra more sparsely and coarsely 

 punctate than there. Length 4-4.5 mm. 



Laporte and Marion counties ; scarce. June 12. 



H. mixtus Lee, 4.1 mm., and H. sericeus Lee, 4.5 mm. in length, 

 both have a range which would indicate their presence in northern 

 Indiana. 



423 (1327). Hydroporus dimidiatus G. & H., Catalog Col., 1870, 432. 



semirufus Lee, Proc. Phil. Acad. Nat. Sci., 1855, 296. 

 Oval, moderately attenuate behind. Pale brownish-yellow ; thorax with 

 a narrow black line on base ; elytra each with seven or eight black spots. 



