502 BULLETIN G3, UNITED STATES NATIONAL MUSEUM. 



It is only by the assiduous working of data and in the making of 

 deductions in accordance with the laws governing ontogenesis and 

 variation that our knowledge will be complete or as full as scientific 

 progress will permit. 



The student must bear in mind that the characters of Blaps given 

 have been draAvn up from a very limited number of species, and that 

 it is to be exjDected that a genus so rich in species will present varia- 

 tions analogous to those observed in Eleodes. I wish to point out 

 that the genus is undoubtedly a divergent stem from the ancestral 

 phylogenetic trunk from which Eleodes also had its origin. A de- 

 tailed study along the lines which I have laid down might be the 

 means of greatly modifying our view of relationships as at present 

 accepted. 



Genus BLAPS Fabricius. 



This well-known genus of the Old World needs no treatment at 

 my hands and is given a place here on account of two species having 

 been introduced into the United States and therefore are to be con- 

 sidered as a part of our fauna. 



In many characters it resembles Eleodes and also ]:>resents several 

 very distinct and divergent characters. 



Mentnm, transverse, plane and more or less variable in form, some- 

 times trapeziform, sometimes rounded at the sides and in front, at 

 times subtruncate, rarely sinuate, ahvays narrowing at base for a 

 short distance. The lateral lobes are small and invisible. 



Maxillary palpi elongate, last joint securiform, longer than wide. 



Labrum prominent, transverse, rectangular or subcordiform. angles 

 rounded and more or less sinuate at middle of the anterior border. 



Head ])rominent, not deeply inserted, frontal suture distinct or 

 obsolete; epistoma with sides more or less straight and convergent 

 anteriorly, apex truncate or feebly sinuate. 



Eyes transverse, narrow, subreniform or sublunate. 



Aiitemuv moderate, 11-jointed, third joint long, I to 7 of variable 

 length, ol)Conical, 8 to 10 globular, 11th oval, pointed at tip. 



Protliorax variable; sometimes almost plane and rectangular, at 

 others more or less convex and rounded at the sides, the latter always 

 margined. 



ScKtclliim of variable size, sometimes not visibk^ 



Elyfni at base not as wide or widei- than the contiguous protho- 

 racic base; form and length variable, frequently attenuated poste- 

 riorly and caudate at apex. 



Epipleura' attaining the humeral angle where the superior margins 

 are visible from abov(\ gradually nai'rowing to elytral ai)ex. Legs 

 generally long, especially the postei'ior; anterior femora more or less 

 thickened ; tarsi moderate, spinous beneath, plantar grooves distinct. 



Prosternvm mucronate or not. 



