24 NATURAL HISTORY BULLETIN 



tibia with three well marked teeth, the upper one the weakest. Hind tarsi 

 long. Length, 6.10 mm. 



Station number 14. One paired specimen collected by Mrs. W. P. Cock- 

 erell; another single example from the same source is referred here with 

 some doubt. The type is in the Museum of the University of Colorado. 



The above short description sets forth the principal characters, 

 as far as they can be made out, of a beetle which I think may be 

 well placed with Serica. However, all of our native species of 

 Serica, so far as I know them, have but two teeth on the fore tib- 

 iae; the fossil agrees more closely with the allied genus Diazus 

 in having three. The body form is more like that of Serica, and 

 I prefer to so place the specimen. The present species is smaller 

 than the average in the genus, but is of almost exactly the same 

 size as the recent S. frociformis, and is also closely approximated 

 in this respect by a new form in my collection, from Buena Vista, 

 Colorado. 



Macrodactylus Latr. 



M. PLUTO n. sp. (Plate VI, Figs. 7, 8.) Preserved in dorsal view and 

 showing parts of the middle and hind legs, the front legs and antennae 

 lacking. Head, across the eyes, a little broader than long, closely and 

 roughly punctured over nearly the entire surface, the vertex more finely, 

 a narrow occipital space about smooth, clypeus truncate and barely emar- 

 ginate in front. Prothorax more finely and sparsely punctate than the 

 head, narrowed at base and apex, strongly angulate about the middle. 

 Elytra broader in front of the middle, not covering the tip of the abdomen, 

 with faint indications of longitudinal striae and apparently finely punc- 

 tured as well. Tibi« (middle and hind) about straight, broader at tip, 

 posterior tarsi long, the first joint about twice the length of the tibial spurs. 

 Length, total, about 12 mm.; of head, 2.00 mm.; of prothorax, 2.85 mm.; 

 of elytron, 6.75 mm. ; of hind tibia, 3.00 mm. ; of hind tarsus, about 4.50 

 mm. Width of head, 2.65 mm.; of prothorax, 4.10 mm.; of one elytron,- 

 2.85 mm. 



Station number 13. One specimen, with reverse, collected by Walter 

 Eeed, while a member of the expedition to Florissant, under the leadership 

 of Professor Cockerell, in March, 1911. The type is in the Museum of the 

 University of Colorado. 



The generic reference is made on the strength of the shape of 

 the prothorax, the sculpture of the head and body, the small eyes, 

 and the long tarsi. In the broad pronotum, this specimen re- 

 sembles some of the Mexican species, but this part must undoubt- 

 edly have been flattened and spread out by pressure. A shred of 



