On the Genus Centrinus and its Allies. 321 
XLIT.—On the Weevil Genus Centrinus and its Allies. By 
Francis P. Pascog, F.L.S. &c., formerly President of the 
Entomological Society. 
In Lacordaire’s ‘Genera des Coléoptéres ’ *—a work without 
an equal of its kind—Centrénus is one of the seven genera of 
“ Centrinides,”’ which, again, form one of the eight subtribes 
of “ Baridiides vrais ;”’ but all these divisions, as well as the 
genera, are subject to exceptions, so as to be incapable of 
being rigidly limited. Centrinus, as defined by Schonherr f, 
is elastic enough to include almost any ordinary Curculionid 
with a slender rostrum; it has for its type Barts bicuspis, 
Germ. In the ‘Munich Catalogue’ 166 species are enume- 
rated ; but probably these are not half the number that exist 
in collections. 
Writing in 1866 Lacordaire defined the genus, but only 
provisionally, and excluding the species having the claws 
united at the base ; and for these, in a note, he pointed out 
that at least three genera were required. ‘The characters on 
which Lacordaire relies in his table of the genera of “ Cen- 
trinides”’ are the rostrum longer than the prothorax and the 
massive rhombic or elliptic body; he admits exceptions in 
regard to the first, and the second is wanting in precision. 
Yet, looking to the immense number of forms } differentiated 
by all sorts of characters, passing into one another without 
any definite limitation, I doubt if anything more satisfactory 
can be devised. 
The pectoral canal in this group is evidently a survival, 
for it is never capable, as in all the normal apostasimerous 
Curculionidz, of receiving the rostrum, which, owing to its 
curve, in many cases very considerable, or to the contiguity 
of the anterior coxe, is prevented from lying in the canal, 
which thus becomes either completely obliterated or remains 
more or less distinct, sometimes continued as far as the meso- 
sternum, but never impinging on it. In some species the 
canal is replaced by a round cavity, which Lacordaire calls a 
cul-de-sac. 
The species are confined to America, the greater number 
to the tropics. Drs. Leconte and Horn § describe twenty-five 
* Tome vii. p. 233. 
+ ‘Curculionidum Dispositio Methodica,’ p. 309 (1826). 
¢ M. Jekel estimates the number of species of Curculionidae in collec- 
tions at 30,000. 
§ “The Rhynchophora of America north of Mexico,” p. 306 (separate 
copy), from the ‘ Proceedings of the American Philosophical Society,’ 
vol. xvi. (1876). 
Ann. & Mag. N. Hist. Ser. 6. Vol. iv. 22 
