402 HETEROMERA. 
of the under surface also in great part) black. The basal joint of the antenne is very 
similarly formed in both sexes, and about as long as the following two joints united, 
the second joint being a little shorter than the third; the anterior tibie have two 
spurs in the male. 
14. Macrobasis megacephala. (Tab. XVIII. figg. 24,3; 24a, antenna, ¢ .) 
Elongate, black, finely and rather densely pubescent ; the pubescence on the head, the scutellum, and the apical 
margin of the elytra cinereous, that on the rest of the elytra blackish-brown; the prothorax cinereo- 
pubescent, with a large oblong patch on either side of the middle of the disc brown-pubescent; the 
pubescence on the under surface cinereous, the ventral segments each with a transverse band in the 
middle extending completely across blackish-pubescent. Head very large and convex, densely and finely 
punctured, with a fine, smooth median line, which anteriorly is of a ferruginous colour, the anterior part 
of the epistoma and the palpi flavous, the labrum deeply emarginate; antenne black or piceous, brownish 
towards the base, slender, setaceous ; prothorax much narrower than the head, as long as broad, the sides 
converging and rounded anteriorly and parallel behind, the disc triangularly depressed in the middle 
before the base, and with a faint median line, the surface very closely punctured; elytra only a little 
broader than the head, elongate, closely and shallowly punctured. 
3g. Antenne with the basal joint slender, thickening a little outwardly, twice as long as the second, unemar- 
ginate on the inner side before the apex; the second joint shorter than the third, equal to the fourth; 
joints 5-11 equal in length. Anterior tibiee with two spurs. Anterior tarsi with the basal joint normal, 
elongate, nearly as long as joints 2 and 3 united. Sixth ventral segment subtruncate. 
Length 194-21 millim. (<¢.) 
Hab. Mexico, Monclova in Coahuila (Dr. Palmer). 
Two male examples, both worn. Closely allied to, and perhaps an extreme form of, 
M. segmentata, from which it may be known by the larger and more convex head, and 
the different colour of the pubescence of the head, thorax, and under surface. The 
antenne are more slender in the male, but otherwise they are formed as in I. segmentata. 
The following species is placed by Dugés in Epicauta, but it belongs to Macrobasis, 
the second joint of the antenne (<¢ ) being comparatively elongate and as long as the 
third. The insect was omitted from the table of species of Macrobasis, antea, p. 395. 
15. Macrobasis basalis. 
Cantharis basalis, Dugés, La Naturaleza, v. p. 144, t. 4. figg. 7, 7 a-d’. 
Epicauta basalis, Dugés, An. Mus. Michoacano, ii. p. 71°. 
Hab. Mexico (coll. F. Bates), State of Vera Cruz! 2, Orizaba (Sailé). 
The female of this insect is so like the same sex of M. albida that I incorrectly 
identified two specimens of it with that species, anted, p. 397; the locality “ Orizaba ” 
must therefore be erased and transferred to I. basalis. The male, of which I have 
since detected an example in Mr. FI’. Bates’s collection, has the basal joint of the 
antenne flattened and curved, and nearly as long as 2 and 3 united, the latter 
subequal, these organs being entirely black (in WM. albida the basal joints are usually 
