136 PHYTOPHAGA.—SUPPLEMENT. 
PACHYBRACHYS (p. 64). 
Most of the American species of this genus are so inconstant in size, shape, sculpture, 
and colour that unless the limit of their variation is known and understood it is almost 
impossible to separate them; and many of those described by Suffrian are, no doubt, 
nothing more than varieties of one or the other of these variable forms. It is the same 
as in the genus Colaspis amongst the Eumolpide and Disonycha amongst the Halticide. 
Fortunately, we have received long series of specimens of many of the Central-American 
species, so that I am enabled to come to a definite conclusion in several instances. 
1 (4). Pachybrachys pubescens. : 
Cryptocephalus pubescens, Oliv. Ent. vi. p. 820, t. 6. f. 91+; Suffr. Monogr. in Linn. Entom. vii. 
p. 148’. 
Cryptocephalus morosus, Haldem. Journ. Ac. Phil. 2nd ser. i. p. 260 (1849)’. 
Hab. Norra America ! 2 3,—Mexico, Northern Sonora (Morrison). 
This species seems to have a rather wide distribution, and is said to be not uncommon 
in different parts of North America. Suffrian has given a detailed description; but 
several specimens obtained by the late Mr. Morrison amongst others of the normal form 
show some very obscure red markings at the sides of the thorax and on the elytra. 
Examples thus coloured resemble P. hematodes, from which they differ, however, in 
shape and other details; this red coloration seems to be peculiar to a greater or less 
degree to the few pubescent species of Pachybrachys at present known. 
1 (s). Pachybrachys thoracicus. (Tab. XX XVIII. fig. 23.) 
Cylindrical, black, pubescent ; thorax finely punctured, the posterior half of the sides bright red ; elytra strongly 
punctured, the interstices subcostate near the apex. 
Length 2 lines. 
Hab. Mexico, Pinos Altos in Chihuahua (Buchan-Hepburn). 
The only, apparently female, specimen I have for examination differs sufficiently from 
P. pubescens to treat it as distinct. P. thoracicus is of an entirely black colour, with 
the exception of a narrow basal margin to the elytra and the posterior half of the sides 
of the thorax (in the shape of a broad triangular space extending inwards to the middle 
of the base), these parts being red; the surface of the thorax is closely and finely rugose- 
punctate and clothed with long whitish hairs; the elytra are similarly pubescent, but 
much more strongly and less closely punctured, the punctures being arranged here and 
there in indistinct rows, the interstices being also minutely punctured and becoming 
slightly convex towards the apex; the underside and legs are black and pubescent, the 
tibiee at the base being very obscurely stained with fulvous. In P. pubescens the elytral 
punctuation is much finer and shows no trace of regular arrangement. P. analis, Lec., 
seems to be an allied species, but is stated to have a red margin to the elytra. 
