MORDELLISTEN A. 339 
53. Mordellistena mutabilis. (Tab. XV. figg. 9,2; 10,3, var.; 11,9, var.) 
Moderately elongate, narrow, subparallel, black, the head pitchy-brown or reddish-testaceous ; the prothorax 
with an obscure testaceous spot at the sides in front in one example; the elytra each with a large flavo- 
testaceous patch immediately below the base (extending to the lateral margin, but not to the suture, and 
obliquely cut off behind) and a large, oblong, obscure testaceous patch on the disc beyond the middle (very 
narrowly interrupted at the suture); the pygidium piceous, reddish at the base; the pubescence on the 
elytral markings yellowish, for the rest partaking of the ground-colour. Head rather elongate, the eyes 
not very large; maxillary palpi testaceous, the last joint elongate-triangular, comparatively narrow, its 
apical side as long as the inner side, the inner apical angle rounded; antenne testaceous, slender, filiform, 
moderately long in the male, considerably shorter in the female, joints 3 and 4 short, together not much 
longer than 5, 4 slightly longer than 3, 5-11 very little stouter, subequal, in both sexes very much longer 
than broad; prothorax nearly as long as broad; elytra moderately long, subparallel in their basal half; 
beneath black, with the apex of the ventral segments, in one example the entire apical one, testaceous ; 
pygidium very elongate and slender; legs testaceous, the hind pair and the middle femora piceous or 
infuseate, the anterior tibie a little thickened in the male; the hind tibie with three oblique ridges— 
the first extending across the outer face of the tibia to near the base, the second much shorter, the third very 
short; the first joint of the hind tarsi with three, the second joint with two, oblique ridges. 
Var.a. The prothorax and elytra black, the latter with a flavo-testaceous oblique spot below the shoulders only. 
(Fig. 10.) . 
Var. 6. The elytra fusco-testaceous, paler towards the base, with the suture—broadly at the base, very narrowly 
beyond,—and the sides at the middle, black or piceous; the sides of the prothorax broadly, the pygidium, 
and the posterior coxe sometimes obscure testaceous ; the apical joints of the antenne slightly infuscate. 
Var. y. Testaceous, the prothorax with a black spot on the disc; the elytra flavo-testaceous, with the base 
narrowly, an angulated ante-median fascia (widening outwardly, interrupted on the disc in one example), 
the suture from this to the base, and in one specimen the apex, black. (Fig. 11.) 
Var. 6. Testaceous, the sides of the elytra narrowly from the base to the middle and the anterior portion of the 
breast piceous. 
Length to end of the elytra 23-8, to tip of the pygidium 3-3], millim. ; breadth 3-1 millim. (¢ 2.) 
Hab. Mexico, Chilpancingo, Teapa (H. H. Smith), Cordova (Sallé), Jalapa (Hoge) ; 
GuaATEMALA, Cerro Zunil, San Geronimo, Lanquin (Champion); Panama, Bugaba, Volcan 
de Chiriqui (Champion). 
A very variable species, according to the predominance of the black or of the testa- 
ceous colour. Ten examples are referred to it: two of the typical form (from Cordova 
and Lanquin), two of the var. a (from Guatemala), three of the var. 6 (from Mexico), 
two of the var. y (from Chiriqui), and one of the var. 8 (from Jalapa). ‘The var. 8 
closely resembles M. luteola and M. distorta; but it is separable from both these by 
its much smaller eyes, and from the former also by its less elongate shape. The var. y 
has the elytra marked very much as in J. crux; but it differs from that species in its 
longer thorax and in the number and arrangement of the ridges on the hind legs. The 
var. « (of which both sexes have been obtained) is perhaps distinct ; it has the elytra 
marked as in UM. curvimana. Numerous North-American forms (some of which, as 
noted by J. B. Smith, are evidently no more than colour-varieties of one or the other) 
are closely allied to this, e.g. WZ. andrew, M. varians, M. ustulata, M. semiusta, &c. 
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