52 HETEROMERA. 
all the species have the intermediate coxal cavities open externally, and the trochantin 
visible and usually very prominent; in Astrotus, however, the cavities are almost 
closed, and the trochantin scarcely visible; the third and fourth ventral segments 
without a coriaceous hind margin. Exceedingly few species of Asidinee are found in 
our country south of Mexico. 
Group ASIDIDES, 
The species of this group are numerous in Mexico and the Southern States of North 
America; none have yet been received from south of Mexico. Two or three new 
genera described here are perhaps best placed in this group. 
ASIDA. 
Asida, Latreille, Hist. nat. Crust. et Ins. x. p. 269 (1804) ; Lac. Gen. Col. v. p. 160 (1859) ; All. 
Abeille, vi. p. 159 (1869); Horn, Revis. Ten. N. A. p. 286 (1870) ; Lec. & Horn, Class. Col. 
N. A. p. 370 (1883). 
Stenomorpha, Sol. Ann. Soc. Ent. Fr. v. p. 487, t. 12. f. 9-14 (1836). 
Pelecyphorus, Sol. loc. cit. p. 467; Lac. Gen. Col. v. p. 159; Lec. Class. Col. N. A. part 1, 
p. 221 (1862). 
Euschides, Lec. Ann. Lyc. New York, v. p. 127 (1852); Journ. Ac. Phil. iv. p. 19 (1858); Lac. 
Gen. Col. v. p. 162 (1859). 
Philolithus, Lac. Gen. Col. v. p. 157 (1859). 
I have not retained Pelecyphorus, Philolithus, or Euschides as distinct from Asida; it 
appears impossible to separate them satisfactorily. The New-World Astd@ are probably 
confined to the southern parts of North America and to Mexico. The North-American 
forms are mostly well known, but of the Mexican species few have been described till 
now, though existing in many collections. 
The species are numerous in Mexico, though none have yet been received from south 
of that country; it is possible one or two may occur in Guatemala. 
The Asida tropica, Kirsch, from Bogota, judging from the description, appears to 
have little to do with Asida, the length given is 43 millim.; the locality, Chili, given 
by Solier for A. asidoides is probably in error for Mexico. Some species of Asida, as 
A. marginata, lirata, polita, convera, convexicollis, &c., found in Arizona and the 
country adjacent to our northern limit, may yet occur in Northern Mexico. 
Certain of the Huschides group have a very different facies from Asida, several super- 
ficially resembling Eleodes, but species occur intermediate which might be placed in 
either. Huschides is well represented in Mexico, and the species numbered 24-35 
belong to it; one or two species (A. villosa and subpilosa) are covered with long, erect 
or decumbent, hairs. 
The different species are found beneath stones in dry arid districts. 
