742 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



those of the other. It is possible that better specimens may prove that 

 the indiviclaals from the two localities, which have here been combined, 

 belong to distinct forms ; but, at present, we see no valid reason for their 

 separation. 



Besides the insects mentioned under the families, but not referred to 

 genera, the collection contains forty-sis species. Of these, the Biptera 

 claim twenty-five, or more than one-half. The proportion in specimens is 

 still greater, since the species belonging to the other suborders are rarely 

 represented by more than a single specimen. Nine different families of 

 Diptera occur, six of them with more than one representative; andof these, 

 so far as the perfect forms are concerned, the lipuUdce and MycetopMlidcv 

 are richest, including several genera wTiich must be considered as new. 

 It will be remarked that, while Tipulidce are more abundant in this col- 

 lection than any other family of insects, they are entirely absent from 

 the collection made by Mr. George M. Dawson in the Tertiary beds at 

 Quesnel, British Columbia,* while the latter collection contains more 

 MycetopMlidce, the next family, than Mr. Denton's. 



The writer is greatly iiidebted to Professor Denton for permission to 

 retain the collection for so long a period. Where no habitat for a species 

 is mentioned, it is uncertain from which of the two localities it was taken. 



HYMENOPTERA. 



Family FoR^nciD^. 



Camponotus vetus. — A single specimen, very fairly preserved, lying 

 upon the side; a remnant of one wing is left, and a faint indication of 

 the antennse, but the legs are wanting. The head has a flat summit, 

 the upper half of the sides roundly protuberant, the lower half rather 

 broad, and tapering but little; the thorax is long and moderately slender, 

 compacted into a single mass, with a low arch, more than twice as long 

 as high. The first segment of the abdomen increases rapidly in size 

 posteriorly, and has a rounded knob above at its hinder end; the abdo. 

 men is long and slender, composed of five joints, the second the largest 

 gradually tapering to the pointed tip. It seems to agree better with 

 Camponotus than with any other genus, but has a differently shaped 

 head and first abdominal joint, and is smaller than the species of that 

 genus, so that it is only placed here provisionally until other and better 

 specimens are obtained. Length of body 3.75™'"; of thorax 1.15™™; 

 of abdomen 2™™. 



Liometopum pinguc. — The single specimen representing this species 

 is a male, as the number of abdominal segments show; but the wings 

 are wanting. The insect is viewed from above. The head and thorax 

 are slightly darker than the abdomen, but otherwise the whole body is 

 uniformly fuscous, somewhat darker than the stone. The head is very 

 small, subquadrate, slightly broader behind, and the posterior angles 

 * See uiy paper in the Report of Progress, 1875-76, Geol. Surv. Canada. 



