TENEBRIONID.E 131 



seemingly but little doubt that sexcostata is properly a member of 

 this genus, although no mention of an inner elytral carina is made 

 by either LeConte or Horn; but, in the figure given by the latter 

 author (1. c.), there is a distinct indication of this carina in a 

 vestigial stage depicted by the artist. 



Besides the species described in the above table, the genus 

 Parasida will include the Mexican Asida scutellaris, fallax, laticollis, 

 favosa, similata and possibly dissimilis, all of Champion, some of 

 which were subsequently reduced to the status of subspecies by 

 their author, though probably too hastily in most instances. 

 Planatula differs from laticollis in its depressed and nearly flat upper 

 surface, in the rounded or lobiform hind angles of the prothorax, in 

 the deep lateral sinuses of the base, in the low and obtuse elytral 

 ridges and scarcely elevated suture. Tolucana is allied rather 

 closely to scutellaris but differs in having the sides of the prothorax 

 not sinuate but rounded basally and in its deeply, rather coarsely 

 and closely punctate intercarinal surfaces of the elytra, with an 

 occasional large deep puncture or irregular tubercle; the brown 

 squamae are only present in a narrow line adjoining each costa, 

 the median part of each interval being broadly subglabrous. Par- 

 asida is one of the larger and more characteristic of the Mexican 



genera. 



Euschides Lee. 



The genus Euschides is by far the largest minor division of the 

 Asidini inhabiting North America and its species exhibit great 

 diversity of outline and sculpture. They are bound together, 

 however, by certain peculiarities of structure, as stated in the table, 

 differing from Pelecyphorus and allied genera in the thick tumescent, 

 angularly incised and non-retractile ligula, and, from the subsequent 

 genera of the table, all of which possess this feature, they differ in 

 the large scalene terminal joint of the male palpi, more particularly 

 distinguishing the Pelecyphorid genera. The form of the thoracic 

 base is so singularly constant throughout all this incongruity of 

 form and bodily facies, that it leads me to consider the formation 

 of the bases of the prothorax and elytra as having a great deal of 

 importance taxonomically ; the base is broadly, subarcuately lobed, 

 somewhat as in the third group of Pelecyphorus and a few other 

 genera and less distinctly in Gonasida; the basal angles are always 



