OPHRYASTES.—TOSASTES. 91 
7. Ophryastes porosus. 
Ophryastes porosus, Lec. Proc. Ac. Phil. vii. p. 225°. 
Hab. Mexico, near Chihuahua !. 
TOSASTES, gen. nov. 
Tarsi articulo tertio vix lobato, subtus absque pubescentia. Tibiw posteriores ad apicem simpliciter laminate, 
nullo modo truncate. 
This genus has an appearance very different to Ophryastes, though it appears to be 
closely allied thereto; as, however, the apices of the hind tibiz are without any trace 
of truncature, or of a second row of spinules, it is perhaps advisable to treat the two 
forms as distinct genera. I cannot detect any other difference of true generic impor- 
tance, though there are several minor peculiarities. The second ventral segment is 
quite short, the first suture straight, the third and fourth segments very short. The 
body is covered with overlapping scales as in Ophryastes. The ocular lobes are well 
developed. 
As remarked above, the facies is very different from Ophryastes; had it not been for 
this I should not have separated the two, as the corbels of the hind tibie are in this 
group in a transitionary condition, and differ from species to species. 
1. Tosastes humeralis, sp. n. (Tab. IV. fig. 4.) 
Ineequalis, rugosus, pallide griseus ; prothorace brevi, ante basin brevissime constricto, angulis posterioribus 
minute prominulis; elytris basi truncato, angulis anterioribus acutis. 
Long. cumque rostro 7-8 millim. 
Hab. Mexico, Chihuahua city (Hége). 
Covered with thin scales, which on the anterior parts are almost entirely fused into 
a continuous indument, bearing also some scanty, very short sete. Rostrum short, with 
a broad median groove and a large lateral impression on each side. Thorax strongly 
transverse, very deeply rugose. LElytra quite truncate at the base, and with the angles 
minutely prominent; very closely applied to the base of the thorax, and of exactly the 
same width, so that the two are almost continuous in outline; the sculpture consists 
of vague, large depressions, placed in series, and connected by obscure strie. Spinules 
at the apex of the hind tibiz excessively short and broad, and very few in number. 
Two specimens. 
2. Tosastes globipennis, sp.n. (Tab. IV. fig. 5.) 
Pallide griseus, obsolete sculpturatus ; coleopteris convexis, humeris rotundatis. 
Long. cumque rostro 7} millim. 
Hab. Mexico, Guajuco in Nuevo Leon (Dr. Palmer). 
This insect differs at first sight from 7. humeralis by the elytra being quite destitute 
NN 2 
