CARABIDiE. 21 



Myas umbrarum sp. nov, 

 PI. I. fig-. 11. 



Several specimens are preserved, but only one is in a condition at all 

 satisfactory. This is preserved both in obverse and reverse, one showing 

 best the upper surface (but as a cast), the other the under surface. As the 

 antennae, legs, and mouth parts are almost all excellently preser^^ed, there 

 is little left to be desired. The species is a little smaller and stouter than 

 the living M. cyanescens Dej. or the fossil M. rigefachis, just described, and 

 has comparatively shorter elytra. The antennae are about three-quarters 

 the length of the elytra, with joints far less moniliform than in the recent 

 species, the first joint much stouter than the rest, the second quadrate, the 

 terminal oval, the remainder subequal, nearly twice as long as broad, and 

 shaped as in the preceding species, but more rounded apically. Laterally 

 the prothorax is regularly and gently convex and delicately margined, with 

 a distinct median furrow and very slightly impressed basal impressions. 

 The elytral striae are not punctured, the first stria is slightly angulate at the 

 base, and outside, from the extreme base of the second stria, running 

 obliquely into it and subparallel to its basal course, is a brief supplementary 

 stria, faintly impressed. The hind tarsal joints are of more nearly uniform 

 length than in M. cyanescens and with shorter terminal spines, and the hind 

 tibiae are not apically dilated to such an extent as in the living species with 

 which we have compared it. The structure of the hind trochanters is 

 exactly as in M. rigefadus, from which species it diifers in its greater 

 stoutness, the more obconic forms of the antennal joints, and the more 

 regularly convex sides of the pronotum. 



Length of body, 11.65 mm.; of elytra, 6.76 mm.; breadth of elytra, 

 4.8 mm.; length of antennae, 4.2 mm.; of hind tibiae, 2.6 mm. 



Florissant, Colorado; three specimens, Nos. 503, 8457 and 9208,14138. 



PTEROSTICHUS Bonelli. 



This is another dominant genus of Carabidae, north temperate in char- 

 acter, though with some Australasian forms, and of which considerably 

 more than a hundred species are known in North America. It has been 

 found in considerable numbers in Pleistocene deposits, half a dozen recent 

 species having been recorded from England, Switzerland, and Galicia, 



