Genera of S.-American Aviculariide. 553 
tibia armed with one internal spine ; palpal organ serrate along 
the convex side of the base of the spine as in Hurypelma 
serratum, but the spine is much thinner than in that species, 
though otherwise similar. 
? .—Like the male in colour, but more hirsute. 
Carapace as long as patella+tibia of first or fourth leg 
(protarsus of fourth scarcely exceeding cephalic area in length), 
and as protarsus and half the tarsus of the fourth, and 
scarcely shorter than tibia and protarsus of second or third. 
A second specimen, perhaps not quite adult, has relatively 
longer legs, the patella and tibia of first and fourth being 
considerably longer than the carapace, the cephalic area of 
which is also much shorter than the fourth protarsus. 
Measurements in millimetres.— 8 (type). Total length 27; 
length of carapace 13, width 12; length of cephalic area 8°5, 
of first leg 47, second leg 45°5, third leg 42, fourth leg 51; 
patella+ tibia of first and of fourth 16, protarsus of fourth 
1455. 
?. Total length 42; length of carapace 18, width 16 
length of cephalic area 12, of first leg 46°5, second 44, third 
41, fourth 52; patella+tibia of first and fourth 18, protarsus 
of fourth 13. 
Loc. Mexico; Guanajuato (A. Dugés). 
Genus APHONOPELMA, nov. 
Anterior side of coxa of first leg thickly clothed with hairs, 
most of which have stout spiniform bases and slender filiform 
extremities; anterior side of trochanter with clothing of 
simple hairs, with at most one or two spiniform sete; no 
plumose scopula on the inside of the femur and no plumose 
scopula on posterior side of trochanter of palp, merely 
simple hairs, and no spines or spiniform sete on the posterior 
side of the coxa of the palp. 
Type Aphonopelma Seemanni, F. Cambr. (sub Hurypelma). 
Distribution. Southern States of North America and 
Mexico. 
I also refer to this genus species from California and Texas 
as well as Hurypelma rusticum. 
Genus PLESIOPELMA, nov. 
Resembling H/ome@ommu in that the base of the protarsus 
of the first leg in the male passes between the two tibial spurs, 
but differing in having the protarsi of first and second legs 
scopulate to base, of third more than half covered below, and 
of fourth with nearly half of it covered. Palpal bulb without 
