58 TERTIARY COLEOPTERA OF NORTH AMERICA. 



Xantholinus tenebrarius sp. nov. 

 PI. VII. %.s. 4-(3. 



The specimen referred here, if it does not belong strictly to Xantho- 

 linus, is certainly nearly allied to it, but it differs from the modern species 

 we have seen, either in nature or in illustrations, in the brevity of the antennae 

 and their apical slenderness. It seems to be nearly allied to X. emmesus 

 Grav., but is of the size of X rudis Sharp of Guatemala. The head is 

 quadrate, longer than broad, narrowing posteriorly to a short neck half as 

 broad as the head; antennae scarcely longer than the head and neck, the 

 first joint long, about one-fourth the length of the whole antenna, enlarg- 

 ing apically to aaearly double the width of the succeeding segments, the 

 second and third of which are quadi-ate, the remainder transversely obovate, 

 the terminal subglobular. Thorax as long as the head, apparently narrower 

 than it, and as seen from a partially side view, it appears to taper forward; 

 it is apparently smooth. The legs are similar to those of X. emmesus, but 

 are proportionally a little shorter, and the tibiae are of perhaps more uni- 

 fonn size. The elytra are considerably longer and somewhat broader than 

 the prothorax and apparently smooth. The abdomen is narrower than the 

 elytra, slender, elongated, with parallel sides, a little enlarged at the fifth 

 ioint, tapering beyond to a rounded extremity, the joints smooth, excepting 

 the last, which bears some bristly hairs toward tip. 



Length, 11.5 mm.; breadth, 1.75 mm. 



Florissant, Colorado; one specimen, obtained by the Princeton museum, 

 Nos. 1.563 and 1.607. 



LEPTACINUS Erichson. 



North America possesses about a dozen species of this genus, and about 

 as many more are scattered all over the globe. The only fossils known are 

 the five here described from Colorado. 



The species we have placed here belong without doubt to the Xantho- 

 lini, but excepting the first and perhaps the second, do not agree with any 

 of the genera of our existing fauna, being remarkable for the shortness of 

 the head, antennae, and thorax, and the relative brevity of the elytra; the 

 sutnral stria is slight and the thoracic punctures do not appear to be 

 aligned; nevertheless, as in the brevity of the parts they share the common 



