352 TERTIARY INSECTS OF NORTH AMERICA. 



position of the others, to be shorter than in Hygrotrechus. The insect is of 

 about the same size as our H. remigis (Say). The head, as seen on a side 

 view, is small and rounded ; thorax minutely scabrous like the head, nar- 

 rowing rather rapidly and uniformly, the posterior limit of the prosternum 

 marked by a. slight depression next the anterior coxae, the whole thorax con- 

 sidrrably longer than broad. Abdomen tapering, the apical angles of the 

 sixth segment produced to a sharp but short spine, reaching- the middle of 

 the succeeding segment. Antennae nearly (perhaps quite) as long as the 

 head and thorax together. Fore femora equal, stout, as long as the thorax; 

 fore tibia? of the same length ; middle and hind legs very slender ; middle 

 femora considerably more than twice as long as the fore femora, the tibia- 

 nearly three times as long as the fore tibia? and of the same length as the 

 hind femora ; hind tibia- a little more than twice as long as the fore femora ; 

 first joint of hind tarsi about one-fifth the length of the hind tibia?. On one 

 of the specimens, preserved on a dorsal view, a line is seen proceeding from 

 either side of the thorax, directly in front of the middle coxa?, and passing 

 toward and nearly to the middle of the hinder edge of the second abdom- 

 inal segment with some distinctness, accompanied on the second and third 

 segments by other lines which seem to indicate the veins of the tegmina, 

 the first mentioned line being the sutura clavi ; but all trace of lines is lost 

 beyond the third segment, as if the wings did not extead over more than 

 half the abdomen ; on the specimen preserved on a side view, they appear 

 to extend to the hind edge of the sixth abdominal segment. Attached to 

 the posterior extremity of the abdomen is a pair of stout lappets, nearly 

 straight, but curving slightly outward, equal, about twice as long as broad, 

 rounded and very slightly produced at the tip. 



In a specimen (No. 70) which I have considered an immature indi- 

 vidual of this species, but which may possibly be a Metrobates, the middle 

 and third femora are of equal length. 



Length of body, 19.75 mm ; of head. 1.5 mm ; of thorax, 5 rara : breadth of 

 anterior extremity of thorax, 1 75 mm ; of posterior extremity, 3.5 mm ; of sixth 

 abdominal segment, 2 mm ; length of fore femora, 5 ram ; of fore tibia?, 5""" ; 

 of middle femora, 12.5 rara ; of middle tibise, 14 mm ; of hind femora, 14"""; of 

 hind tibia?, 11.5 mm ; of first joint hind tarsi, 2.3"""; of abdominal lappets, 

 1.3 mm ; breadth of hind femora, 0.35"' ra ; of hind tibia, ().2" im ; of hind tarsi, 

 0.1 5 mm . 



