COLEOPTERA— HYDROPHILID^. 513 



LACCOBIUS Erichson. 

 Laccobius elongatus. 



PI. 7, Figs. 27, 28. 

 Laccobius elongatus Scudd., Bull. U. S. Geol. Geogr. Siirv. Terr., IV, 761 (1878). 



A single specimen and its reverse exhibit the elytron of a slender 

 species of Laccobius. It is more than two and a half times longer tlian 

 broad, and is furnished with thirteen equidistant, delicately punctured, 

 faintly impi-essed strife, the punctures of which are more apparent on the 

 basal than on the apical half ; the inner stria is as distant from the sutural 

 border as from the neighboring stria, while the outer is scarcely separate 

 from the outer margin. The species is very large, and also very slender, 

 for a Laccobius, in which genus, however, I am inclined to place it, from 

 the large number of punctured striae. The elytron has much the general 

 appearance of that of a Lebia, but the number of striae, of course, forbids 

 such a reference. 



Length of elytron, 2.9"""; breadth, l.l"""". 



Green River, Wyoming. One specimen, No. 81* and 136^ (Mr. F. C. 

 A. Richardson). 



BEROSUS Leach. 

 Berosus sexstriatus. 



PI. 7, Fig. 40. 

 Berosus sexstriatus Scudd., Bull. U. S. Geol. Geogr. Surv. Terr., IV, 760-761 (1878). 



A single well preserved elytron represents a species scarcely smaller 

 than B. punctipennis Chevr. (undescr.^) from Mexico, with the elytra of 

 which it also agrees in the character of the tip and in the shape of the whole,, 

 unless in the fossil it tapers more toward the base ; the latter is also remark- 

 able for the absence of the two lateral striae, the others retaining their nor- 

 mal position ; and for the delicacy of the strife themselves, which are even 

 more faintly impressed than in B. cuspidatus Chevr., and, unlike all Berosi I 

 have seen, are nearly devoid of any sign of punctuation ; faint traces only 

 can be seen when magnified twenty-five diameters. As not unfrequently 

 happens in Hydrophilidae, although I have not noticed it in Berosus, a 



'Seen in tlie collectii)u of tlie late Mr. George D. Smith. 

 VOL. XIII 33 



