16 | HETEROMERA, 
Subfam. TENEBRIONINA. 
With this subfamily we commence a series of species in which the hind margins of 
the third and fourth ventral segments are more or less coriaceous, the intermediate 
coxee usually with a distinct trochantin. 
We adopt in great part, as with the Tentyriine, the arrangement used by Dr. Horn 
for the North-American species, the Central-American Tenebrionide, so far as at 
present treated, partaking very largely of the character of the fauna of that region. 
No species of the tribe Amphidorini has yet been received from our country; the 
three North-American genera (Amphidora, Cratidus, and Stenotrichus) are found in 
Arizona and California. 
Group BLAPTIDES. 
This group will include Elwodes only. Allied genera (Embaphion, Trogloderus, and 
Discogenia) are found in North America. 
ELAODES. 
Eleodes, Eschscholtz, Zool. Atlas, iii. p. 9 (1829) ; Solier, Studi Ent. p. 235; Lacord. Gen. Col. v. 
p- 148; Lec. Class. Col. N. A. p. 225; Horn, Rev. Ten. N. A. p. 301; Lec. & Horn, Class. 
Col. N. A. p. 374. 
Xysta, Eschsch. loc. cit. p. 9; Guérin, Mag. Zool. 1884, Mélasomes, p. 30. 
Promus, Leconte, Class. Col. N. A. p. 226. 
Blapylis, Horn, Rev. Ten. N. A. p. 315. 
Eleodes, Gemm. & Harold, Cat. vii. p. 168. 
Upwards of 100 species are placed under this genus in Gemminger and Harold’s 
catalogue—twenty-six from Mexico, the remainder from North America. Seven 
Mexican species (not included in the above catalogue) were described by Say in 1835 
in the ‘ Boston Journal of Natural History ;’ some of these are probably identical with 
others subsequently described by Solier, and included under other names in Gemminger’s 
list. Dr. Horn, in his ‘ Revision of the Tenebrionide of America north of Mexico,’ gives 
forty-six species as inhabiting the United States: this author here sinks, as synonyms 
or varieties, nearly one third of the previously recorded North-American species. 
It is quite impossible, without comparison with the actual types, to identify many of 
the Mexican species described by Say and Eschscholtz; the correct determination in 
consequence, from description only, of some of the species of these authors is doubtful. 
To increase the difficulty of satisfactorily determining or separating the numerous 
species of this genus, the shape of the thorax, the structure of the femora, tarsi, &c. is 
not always symmetrical or constant, and sometimes different on one side of the body 
from the other. Aberrations of this kind are frequent in the Tenebrionide. 
We have now to record fifty-two species from Central America, all from Mexico, one 
only extending into the highlands of Northern Guatemala, the southern limit of the 
genus; ten of these species also inhabit the country adjacent to our northern frontier. 
