20 



NATUEAL HISTOEY BULLETIN 



served, considerably exceeding the elytral apices. Hind femora strongly 

 swollen, each apparently with a good-sized tooth, though this structure is 

 indistinct, hind tibiae much arcuate. Length, 3.25 mm.; of elytron, 2.00 mm. 



A considerably smaller species than most of those hitherto re- 

 corded from Florissant. It seems nearest B. osborni in antennal, 

 thoracic, and sculptural characters, but that species is much 

 larger. The measurements given for B. tvilsoni are those of the 

 type, others are as small as 2.65 mm. It is named for George "W. 

 Wilson of Florissant, to whom I am indebted for many favors 

 which materially assisted me in the investigation of the fossil 

 insect fauna. 



For the purpose of more readily distinguishing the Florissant 

 species of Bruchus, I subjoin the following table. 



Antennae strongly serrate; (3.7.5 mm.). dormescens. 



Antennae weakly or moderately serrate. 



Larger (4.35 mm.). Thoracic punctures shallow. exhumatus. 



Smaller (3.90 mm.). Thoracic punctures strong. scudderi. 



Antennae not serrate. 



Elytral striae with strong rounded punctures; (4.15 mm.). henshaivi. 

 Elytral strial punctures weaker, elongate. 



Large species (6.00 mm.). ioivditchi. 



Smaller species. 



Prothoracic punctuation moderately close; (4.00 mm.). 



florissantensis. 

 Prothoracic punctuation strong, deep, becoming subconfluent in 

 places; (2.25 to 3.50 mm.). succintus. 



Prothoracic punctuation very fine and sparse. 



Thoracic apex truncate. Punctuation stronger; (4.65 mm.). 



liayicardi. 

 Thoracic apex rounde<l. Punctuation finer; (4.45 mm.). 



oshorni. 

 Elytral striae impunctate; (2.65 to 3.25 mm.). u-ilsoni. 



Pythoceropsis n. gen. 



Form similar to that of the recent genus Lecontin. Anterior coxae round, 

 separated by the prosternum, middle coxae slightly transverse and apparently 

 only a little separated, their inner edges obscured by the anterior femora 

 which have been folded back. Posterior coxae transverse, extending to the 

 sides of the body, contiguous on the median line, intereoxal process short. 

 Antennae not clubbed, but slender at the apex, first joint large, second much 

 smaller, third elongate, fourth fifth, sixth, and seventh subequal among 

 themselves and each shorter than the third; the eighth, ninth, tenth and 

 eleventh are much shorter than those preceding, the eleventh probably dam- 

 aged at the apex. The type is P. singularis, described below. 



