36 MADEIRAN COLEOPTERA. 
A, oblong, deep-black (except when immature), rather distinctly 
punctured, pubescent, and slightly shining. Head triangular, 
more acute in front (between the antenne) than in any of the 
preceding species,—the labrum being prominent. Prothorax ra- 
ther short, and scarcely broader than the elytra; almost equally 
rounded at the sides, and with its posterior angles slightly pro- 
duced and concolorous with the rest of the surface. Elytra two- 
thirds longer than the prothorax, and jointly as long as broad ; 
with their hinder margin a little paler ; of nearly equal breadth to 
two-thirds of their length, and from thence gently rounded; and 
very much shorter than the abdomen,—which is greatly length- 
ened-out, so that its four or five hinder segments are exposed. 
Antenne shorter and darker than in any of the other species here 
enumerated, and with the basal joint of their club somewhat 
smaller; the first and second joints more or less rufo-piceous. 
Legs testaceous,—except the femora and cove, which are rufo- 
piceous. Hind cowe of moderate size. 
The oblong outline of the present Acratrichis, which is more acute 
both before and behind than its Madeiran allies, in conjunction. with 
the shape of its prothorax, its shorter and darker antenne, and its 
much-lengthened, exposed abdomen, will at once distinguish it from 
the remainder of the genus here enumerated. 1 am indebted to 
Mr. Haliday, not only for comparing it carefully with his large col- 
lection of the Ptihade, but also for correcting my diagnosis of it; 
and Iam glad to be enabled to state, on his authority, that he be- 
lieves it to be unquestionably new, since his extensive acquaintance 
with the members of this minute family renders his opinion doubly 
valuable. In its elongated form and pointed head it agrees with the 
suffocata, Hal.; but Mr. Haliday remarks that that species he be- 
lieves ‘‘ to be most closely allied to the first group of the genus 
(atomaria, grandicollis, fascicularis, &c.), by the more significant 
characters of the form of prothorax, the very large hind coxe, and 
the broader and more keeled mesosternum;’’ whilst the Madeiran 
obsceena he regards “as more akin, by its less widened prothorax 
(the basal angles of which are less produced), smaller hind coxee, and 
the narrower keel of its mesosternum, to the sericans,” &e. Mr. Hali- 
day has indeed been kind enough to grant me the loan of his typical 
specimens of the suffocata (discovered by himself in the county of 
Cork); and, in addition to the above (almost sectional) characters, 
of prothorax, mesosternum and coxe, it is very much larger and 
broader than the obsceena, its abdomen is not quite so much un- 
covered (three or four segments only being visible, instead of four 
or five), and its antenne are longer and paler. 
The A, obscena was detected by myself, beneath the dung of cattle, 
