324 HETEROMERA. 
24. Mordellistena crassipalpis. (Tab. XIV. figg. 16, ¢ ; 16a, antenna; 
16 6, maxillary palpus; 16 ¢, hind leg.) 
Elongate, subparallel ; the head reddish-testaceous, with the eyes and a large transverse patch on the vertex 
(sometimes not quite reaching the eyes or occiput) black ; the prothorax reddish-testaceous, with an oblong 
median patch on the disc behind, excised in the centre in front, the base broadly, and in one example 
the apex in the middle, black; the scutellum, elytra, and pygidium black; the pubescence coarse and 
dense, that on the elytra consisting of intermixed black and yellowish-cinereous hairs. Maxillary palpi 
(3) testaceous, piceous at the tip, exceedingly stout, the second joint much thickened, the apical joint 
comparatively short, sharply triangular, its inner and apical sides equal in length; antenne short and 
stout, black, the basal four joints reddish, joints 3 and 4 short, equal in length, 5 nearly twice as long as 
and very much stouter than 4, 5-10 decreasing in width, equal in length, not very much longer than 
broad ; prothorax a little broader than long; elytra elongate, subparallel in their basal half; beneath, 
the head and prothorax excepted, black, brownish-cinereous-pubescent; pygidium moderately elongate, 
about twice the length of the hypopygium; legs comparatively stout, black, the anterior femora and 
tibiw, the middle femora, and the hind tibial spurs testaceous; the hind tibie and the first joint of the 
hind tarsi each with three or four, the second joint of the hind tarsi with two or three, short, oblique 
ridges. 
Length to end of the elytra 4, to tip of the pygidium 43, millim.; breadth 1} millim. (<.) 
Hab. Mexico, Guanajuato (Sallé), Tupataro in Guanajuato (Hoge). 
Three examples. Very like WZ. pilosa, but with the thorax less transverse; the 
antenne shorter and stouter, the fifth joint stouter than the sixth; the maxillary palpi 
very much stouter, the apical joint not nearly so elongate and sharply triangular, the 
second joint much wider ; the elytral pubescence not uniform, but consisting of inter- 
mixed black and yellowish-cinereous hairs. In this species the maxillary palpi are 
unusually stout. 
25. Mordellistena instabilis. (Tab. XIV. figg. 17,¢; 18, 3, var.) 
Moderately elongate, cuneiform, black or piceous, the mouth-parts testaceous, in some examples the sides of 
the prothorax and the elytra and pygidium in part reddish-brown; the elytra each with two fascia of 
variable size—one below the base, oblique, extending to the shoulders, the other, oblique or transverse, a 
little beyond the middle, the two often connected laterally,—the apex, and the suture, more or less, 
yellowish-cinereous-pubescent, the rest of the pubescence black, the markings in dark examples entirely 
formed by the colour and arrangement of the pubescence, in the light ones accompanied by a difference in 
the ground-colour; the pubescence on the head, prothorax, scutellum, and pygidium yellowish-cinereous. 
Head with or without a slight opalescent lustre; palpi testaceous, the last joint of the maxillary pair 
moderately stout, subtriangular, a little longer in the male than in the female; antennew comparatively 
short, still shorter in the female, testaceous, the outer joints sometimes darker, joints 3 and 4 slender, 
4 very little stouter than 3, 5-11 subfiliform, 5 stouter than and nearly twice as long as 4, 5-10 decreas- 
ing slightly in length, equal in width, all much longer than broad; prothorax transverse; elytra 
gradually narrowing from the base; beneath black, the prothorax and venter often in great part rufous ; 
pygidium very elongate, twice the length of the hypopygium ; legs variable in colour—the two front pairs 
usually testaceous or reddish and the hind pair piceous, the latter sometimes reddish ; the hind tibie with 
four or five (including the subapical one), the first joint of the hind tarsi with three or four, and the 
second joint with two, short, oblique, parallel ridges. 
Var. a. The prothorax rufous or rufous with the disc indeterminately piceous. 
Var. B. The head only rufous, the prothorax and elytra black, the markings of the latter formed entirely by 
the colour and arrangement of the pubescence. 
Var. y. The head and prothorax rufo-luteous, the disc of the latter slightly infuscate. 
