516 ' TERTIARY INSECTS OF JfORTH AMERICA. 



properly represent the prominent rounded humeral angle. It differs from 

 the modern species mentioned in wanting the special prominence of the 

 third and fifth interspaces over the intermediate ones, though the seventh 

 and eighth are elevated ; the punctures are also a little less ])ronounced, 

 and so the interspaces wider ; whence doubtless it liappens that the minute 

 hairs which are confined to a single pretty regular row in the interspaces of 

 the living species are scattered, irregular, and more numerous in the fossil. 



Length of fragment, 2.6""" ; probable length of elytron, 2.8™'" ; its 

 breadth, 1"'"'. 



Interglacial clay beds of Scarboro, Ontario. One specimen, No. 

 14504 (G. J. Hinde). 



Hydrochus relictus. 



PI. 8, Fig. 11. 



Head rather large, rounded, subtriangular, broader than long but 

 prominent; eyes moderately large, globular, somewiiat projecting. Thorax 

 cylindrical, broader than long, a little broader than the head, broadest in 

 the middle and narrowing a little both in front and behind, the sides slightly 

 and rather regularly rounded, front and hind border nearly straight, the 

 surface apparently a little roughened and with very short, moderately 

 stout, scattered hairs, or perhaps only the latter. Elytra together much 

 broader than the thorax, with well rounded humeral angles and with ten 

 longitudinal jjunctate striae (the innermost and outermost not shown in the 

 plate) marked by short, moderately stout, scattered hairs, about half as 

 long as the width of the interspaces. 



Length of body, 3"""; of thorax, 0.6""'; of elytra, 2'""'; breadth of 

 thorax, O.D"""; of elytra, 1.3"°". The specimen is seen from above but with 

 a partially lateral view; if it were wholly dorsal the width of the elytra 

 would probably be L7""". 



Green River beds, Wyoming. One specimen. No. 88 (Dr. A. S. 

 Packard). 



HELOPHORUS Illiger. 

 Helophorus rigescens. 



PI. 1, Fig. 53. 

 A single elytron with a broken tip represents this species, which does not 

 seem to agree closely with any modern form, having less heavily punctate 



