MORDELLA. 299 
43. Mordella biformis. (Tab. XIII. figg. 3,3; 3a, antenna, 30, maxillary 
palpus, ¢; 4,2; 4a, maxillary palpus, ? .) 
dg. Elongate, rather narrow, black ; the mentum and mouth-parts (the tips of the mandibles excepted) testa- 
ceous ; the head cinereo-pubescent; the prothorax rather broadly bordered on all sides with cinereous 
pubescence, which in one or two examples extends upwards on either side of the middle to the anterior 
margin so as to enclose three large oblong ill-defined spots, the rest of the surface sparsely clothed with 
blackish pubescence ; the scutellum cinereo-pubescent; the elytra each with two short stripes (often 
confluent) placed parallel to each other near the suture some distance before the middle—the external 
one curving outwards, extending forwards to the base and continued along it to meet a triangular scutellar 
patch (nearly or quite enclosing a large oblique black spot), and more or less coalescent with an oblique 
post-humeral stripe,—and a long comma- or c-like mark on the dise beyond the middle cinereo-pubescent, 
the rest of the pubescence black; the pygidium cinereo-pubescent at the base, black beyond.  Palpi 
testaceous, the apical joint of the maxillary pair infuscate, the latter very stout, securiform, and thickly 
clothed with hairs beneath ; antenne black with the basal three or four joints testaceous, long, joint 3 
slender, 4-11 much longer than broad, moderately widened, 4-8 serrate (5-7 more distinctly so), 9-11 
narrower; elytra moderately long; beneath black, the sides sometimes with a metallic violaceous or 
eeneous lustre, the venter piceous, the last two segments a little paler, the pubescence in part cinereous, in 
- part black ; pygidium rather slender, long and acuminate, compressed at the sides, nearly twice as long as 
the hypopygium ; legs piceous or black, the anterior femora in great part and the coxe flavous, the inter- 
mediate femora (except at the apex), and sometimes the base of the anterior tibis reddish-testaceous, the 
tibial spurs testaceous, those of the posterior pair very unequal in length (the i inner one twice as long as 
the outer one); the anterior tibie slightly curved. 
Q. Broader; the last joint of the maxillary palpi much smaller and narrower, its apical and outer sides about 
equal in length, each very much shorter than the inner side; the antenne with joints 4-8 a little less 
widened ; the prothorax rufous, with the sides and apex narrowly infuscate or black; the pygidium, 
except at the tip, and the last two ventral segments more or less rufous ; the anterior and intermediate 
femora darker ; the anterior tibie straighter. 
Length to end of the elytra 33-43, to tip of the pygidium 43-5), millim.; breadth 13-2 millim. (¢ 9.) 
Hab. Murxico, Cerro de Plumas, Oaxaca (Hage), Cordova, Tehuantepec (Sallé), Teapa 
(H. H. Smith); Britisn Honpuras (Blancaneauax) ; GuateMALA, Cahabon, Chiacam, San 
Juan, and San Gerénimo in Vera Paz, Zapote (Champion), Coban and Panzos (Conradt). 
This is one of the commonest species of Mordella in Southern Mexico and Guate- 
mala, whence we have obtained a large number of examples. The sexes, both of which 
have been obtained in most of the above localities, differ considerably in the colour of 
the thorax and in that of the terminal segments of the body, as well as in the shape 
and clothing of the apical joint of the maxillary palpi. The cinereo-pubescent markings 
of the elytra are sometimes reduced a little in size, sometimes much more extended ; 
the comma-like mark on each elytron beyond the middle is always distinct. The 
thorax usually has the base, apex, and sides cinereo-pubescent, the rest of the surface 
being only very sparsely pubescent. In the rufous thorax, terminal ventral segments, 
and pygidium the female closely resembles the corresponding sex of the following 
species. The sexes of the European Mordellistena abdominalis (Fabr.) differ from each 
other in colour in a somewhat similar way. The N.-American I. oculata, Say (= jovi- 
alis, Lec.), seems to be an ally of MW. biformis. 
