290 MEMOIRS ON THE COLEOPTERA 



elytron, two very fine and subobsolete though rather sharply marked 

 longitudinal raised threads. 



Simplicicornis and rector are perhaps allied to armata Lee., and 

 generally figure among the representatives of that species in collec- 

 tions; but, on consulting the original description of the type of 

 armata, which was found by the Mexican Boundary Survey, it is 

 evident that they cannot be identical with LeConte's species. The 

 species just mentioned have the lateral thoracic spines so small as 

 to be little more than acute tubercles and could never, in my opinion, 

 have given rise to such a name as armata; they are also very much 

 smaller in size, armata, in fact, being one of the largest species of the 

 genus (1.25 inch or 31.2 mm). It is probable that the original type 

 of armata has never been duplicated, and that the species is allied 

 rather with the gigas group, but having more rugulose elytra. The 

 species from constricta to pollens in the table, are allied more espe- 

 cially to gigas Lee., but are all materially smaller; furthermore in 

 only one, pimalis, do the thoracic spines approach the development 

 that they have in gigas, and in pimalis they are much more slender. 

 The length of gigas, as given in the original description, is 37 mm. 

 G. H. Horn (Trans. Am. Ent. Soc., 1885, p. 185) gives the length of 

 gigas as somewhat less, that is 30-34 mm., all of which measure- 

 ments are materially greater than any pertaining to the species of 

 the group named above, which range from 22 to about 28 mm. 

 Individuals of the same species do not vary so greatly in size in this 

 genus. 



The two subgeneric divisions adopted above on the recommenda- 

 tion of Dr. Horn (1. c.), are quite distinct in habitus, as may be 

 observed very readily on segregating the groups, and possibly it 

 would be better to give them generic rank, but there are no very 

 sharply marked differences in the tarsi; in solida, for instance, the 

 first joint of the posterior is nearly as long as the next two combined, 

 but in the rather closely allied femoralis it is very much shorter, 

 being only a little longer than wide ; they are however always thicker 

 in Collapteryx than Moneilema proper. The pads of dense pubes- 

 cence on the soles of the tarsi offer comparatively little diversity 

 of form or extent in the species here defined, and so no use has been 

 made of a character that may, in certain aberrant forms such as 

 fortis Lee., become very conspicuous. 



