no. 2358. NEW SPECIES OF FOSSIL INSECTS— COCKERELL. 33 



Eocene. U. S. G. S. 367; White River, Colorado. This is clearly 

 one of the Clitellarinae, and is referred to Nemotelus because that is 

 one of the dominant genera, and the characters do not distinctly 

 contradict the reference. It is very likely, however, that if we knew 

 the antennae and scutellum it would be possible to recognize a distinct 

 type, now extinct. 



Holotype.— €at. No. 66924, U.S.N.M. 



Family MUSCIDAE (sens. lat.). 



ACANTHOMYITES, new genus. 



Rather stout flies of moderate size, with thick (deep, not narrowly 

 cylindrical) abdomen ; wings not preserved in the type. Characterized 

 by the great number of large dark bristles on head, abdomen and legs. 



6 / / n\^ 



7/4 # 



if 



FIG. ">.— ACANTHOMYITES ALDRICH1. DlA- FlG. 6.— ACANTHOMYITES AL. 



GRAMJ1ATIC FIGURE OF DORSAL BRISTLES DRICHI. ANTERIOR LEG. 



OF THORAX. 



The largest are the acrostichals on thoracic dorsum, but the dorsocen 

 trals appear to be very small. An attempt has been made in the 

 accompanying figure to diagrammatically show the distribution of the 

 dorsal thoracic bristles, but it is not exact, and the sutures can not be 

 seen at all. The bristles on abdomen, head, and legs are smaller 

 than the acrostichals ; there is the usual row on the underside of the 

 anterior femora. 



Type. — Acanthomyites aldrichi, new species. 



ACANTHOMYITES ALDRICHI, new species. 



Plate 8, fig. 12. 



Length, nearly 6 mm. ; as preserved brown, the sides of the abdo- 

 men pallid. Head rather small; legs of moderate length, not espe- 

 cially robust. 



Eocene. " Cathedral Bluffs south of Little Tommies Draw at 

 point where samples were taken." (Winchester, 17-5; U. S. G. S.) 

 Colorado. Named after Dr. J. M. Aldrich, who examined it when 

 visiting my laboratory, and agreed that such an interesting form 

 ought to be recorded, in spite of the loss of the wings and other impor- 

 tant features. It is certainly a striking circumstance that the system 

 27177 :->1 ProcXM.voi.59 3 



