190 MEMOIRS ON THE COLEOPTERA 



size; antennae very thick, joints three to seven increasing uniformly and 

 rapidly in size, transverse; prothorax slightly more than twice as wide as 

 long and somewhat less than a third as long as the elytra, the converging 

 sides almost evenly, strongly arcuate; pubescence coarse, ashy, sparse and 

 scarcely at all variegated; punctures small and widely separated; basal 

 sinuses slightly impressed near the median lobe; elytra as wide as the 

 prothorax, about a third longer than wide, parallel, evenly rounded 

 in about apical third; punctures only moderately coarse but deep, rugose 

 and close-set, giving a dull and very rough surface; under surface strongly 

 convex, inconspicuously pubescent, rather finely but strongly, very closely 

 punctate throughout; hind tarsi not three-fourths as long as the tibiae. 

 Length (cf) 2.8 mm.; width 1.7 mm. District of Columbia. 



This species differs from any other of the inclusa group in the 

 very rough dense sculpture of the elytra, and, from inclusa, it differs 

 in its rather more elongate outline, much smaller or obsolescent red 

 areas of the elytra and less broken and irregular system of more 

 densely pubescent lines on the latter. 



On examining the male antenna of Trogoderma serrifera, I find 

 a marked agreement with that of Eucnocems dispar Shp., as depicted 

 in the "Biologia," though the part just beyond the second joint does 

 not fit very well. In serrifera, the joints are attached very nearly 

 at the extreme sides as in dispar, but in parvula, described above, 

 belonging to the same group as serrifera, the points of attachment are 

 slightly less lateral. In slernalis and others of that group, the 

 joints are more symmetric and the pedicels are only slightly though 

 evidently eccentric, and, finally, in inclusa and others of that group, 

 characterized by sinuate eyes, the pedicels are so nearly in the an- 

 tennal axis, that their eccentricity would not be noticed unless 

 looked for carefully. I believe that Eucnocerus is undoubtedly a 

 valid genus and it is quite possible, as suggested by Dr. Sharp, that 

 some of our species, such as serrifera, can be associated with its 

 Yucatan type, but, as the males of many of our species, especially 

 as assigned provisionally to the serrifera group, are not yet known, 

 I do not deem it prudent to make any definite transfers to it at 

 present. 



Cryptorhopalum Guer. 



The body in this genus is usually more briefly oval than in the 

 preceding and has much thicker integument. The antennae differ 

 radically in having a very compact, elongate-oval, 2-jointed club, 

 almost similar in the sexes, though the entire antennae, as well as the 



