AMERICAN COLEOPTERA. 295 



which is scarcely at all transverse ; these also may, I think, be fairly 

 considered no more than .local races of sphcericollis. 



On leaving the arid regions and passing over the mountains into 

 the true Pacific fauna, we encounter a form, of which examples from 

 Northern California (Shasta and Siskiyou Counties) may be con- 

 sidered typical, that seems worthy of a specific name ; it may be 

 called infidelis. In this the thorax is distinctly more elongate and 

 less convex than in sphcericol/is, the color is deep blue, and the size 

 rather greater on the average. With these I have also placed a 

 series of black specimens from the vicinity of San Francisco. 



Specimens bearing the label compressicornis are in most collec- 

 tions, but in the material sent me for examination these are all 

 sph(ericollis. The former should be known by the strongly trans 

 verse intermediate antennal joints of the male. These same joints, 

 as Mr. Blanchard writes me after examining the LeConte series, 

 are distinctly concave as though fitted for clasping ; a character 

 which Mr. Liebeck has more recently verified for me in the Horn 

 types. In sphcericollis the same joints are as long as wide or very 

 nearly so. 



It seems not to have been remarked that in all the species of this 

 group (presumably — though I have not verified it in couvSica), the 

 front tibiae are densely pale pubescent on the inner side in both 

 sexes, almost throughout their length. 



In view of the numerous additions and changes since Horn's most 

 excellent Review* of the species in 1878, it has been thought worth 

 while to embody in a single table these .somewhat scattered observa- 

 tions and corrections. Following the table will be found brief de- 

 scriptions of the forms here recognized as new. 



Antennse of male with intermediate joiuts either deformed or thicker than those 

 which precede or follow. Anteunse more or less moniliform iu both 

 sexes, gradually stouter to tip in the female and not much longer than 

 the head and thorax ; longer, but never equal to half the length of the 

 body in the male Group 1. 



Antennee not appreciably dissimilar in structure in the sexes, though usually 

 somewhat longer in the male ; either moniliform or slender; in several 

 species longer than half the length of the body Group II. 



Antennae with compressed joints; joints 5-10 subquadrate or distinctly trans- 

 verse; thorax convex, somewhat globose in form: both hind tibial 

 spurs slender and acute; .front tibiae densely pubescent on the inner 

 side Group III. 



* Proc. Am. Phil. See, 1873, p. 103. 



TRANS. AM. ENT. SOC, XXVII. AUG., 1901. 



