452 TERTIARY INSECTS OF NORTH AMERICA. 



nrina very faint, but the corium apparently terminating just before the tip 

 of the scutellum. Extremity of the abdomen very broadly rounded. The 

 whole surface of the head, thorax, scutelluni, and probably of the corium 

 uniformly, very profusely, and minutely punctulate, otherwise smooth, 

 excepting that there are also faint traces of a. slight, transverse, median depres- 

 sion, and a similar longitudinal median depression on the thorax. 



Length of body, f>.2o ram ; of head, 1.2'""' ; of thorax, 1.3 mm ; of scu- 

 tellum, 1.65 mm ; breadth of head, 2 mm ; of thorax, 3.5 mm ; diameter of eye, 

 0.25 mffi 



Green River, Wyoming. One specimen, No. 4l!><). 



6. DISCOSTOMA nom. nov. (Sioito?, 



This name is proposed for Lobostoma Am.-Serv., preoccupied in mam- 



mals. The genus is composed of only two or three species found in Cen- 



tral America and Guiana. It has never been recognized in a fossil state, 



and the specimen from Florissant is referred to it only tentatively until 



better material is at hand. 



1 >ISCOSTOMA ''. sp. 

 PL 22, Fitf. ('.. 



The ventral surface of an exceptionally large cydnid, showing the 

 abdomen and a part of the legs and little more, is all that remains of the 

 single specimen referred here. From its size one would naturally refer it 

 to this genus or its neighbors, which contain the largest species of the 

 group; and besides, the hind tibiae are furnished exteriorly, as in existing 

 species of Discostoma, with a single line of line spinnles, the only charac- 

 teristic available; whether the tibia? are cylindrical orflattened can not in- 

 told. The abdomen is dark griseous, with a pale rounded semicircular 

 spot seated on the outer margins of each segment, separated from its neigh- 

 bors by the darker incisures, besides which the apical margin of the first 

 segment shows a narrow, blackish fuscous licit. Legs pale, the spines 

 blackish; only the basal part of the hind tibia- seen 



Probable length of body, 18 mm ; breadth of abdomen. 8 mm ; length of 

 hind femora, 5""". 



Florissant, One specimen, No. 234. 



