334 RHYNCHOPHORA. [ Ceuthorrhynchina. 
prosternum very narrow between the anterior 
COxe, 
A. Rostrum about six times as long as broad, 
shining in front; sides of thorax without 
tubercles . rs oP . Amatus, Schinh. 
B. Rostrum short and broad, only two or . three 
times as long as broad ; sides of thorax with 
more or less distinct tubercles. 
a. Tibiz and tarsi furnished sparingly with 
long tatatory cilia; third joint of tarsi 
narrow, without distinct lobes . . . Evsrycuivs, Thoms. 
b. Tibiz and tarsi without cilia; third joint of 
tarsi widened and deeply bilobed. 
a®*, Antenne inserted in middle of rostrum ; 
last joint of tarsi elongate . . Liropactyxvus, Redt. 
b*, Antenne inserted in front of ‘middle of 
rostrum; last joint of tarsi not elongate PHyrosius, Schmidt. 
MONONYCHUS, Schonherr. 
This genus contains about ten species, five of which are found in 
Europe, and the remainder in Siberia, China, Central Asia, the Canary 
Islands and North America; they are moderately large, convex and 
thick-set insects, and may be known by having the onychium furnished 
with a single claw, and the scape of the antennz only half as long as 
the funiculus ; they live in the pods of species of J7is. 
The larva of the single British species, M. pseudacori, is described and 
figured by Westwood (Classification I. p. 345, fig. 41, 20); it consider- 
ably resembles the larva of the nut weevil (Balaninus nucum), being 
short, thick, tubercular, and without hairs ; it feeds in the pods of Iris 
pseudacorus and is found in profusion in some parts of the Isle of Wight 
in the seeds of this plant in August ; the beetle eats its way out of the 
seed and pod and, after hybernating, deposits its eggs in spring, like the 
other weevils, 
NM. pseudacori, F. Black, slightly glossy, form stout and broad ; 
head hollowed between the eyes which are large, with a few ferruginous 
seales at the base of the rostrum ; rostrum moderately long and slender, 
a little dilated at apex ; antenne reddish testaceous with the club dark ; 
thorax narrowed in front, rounded and somewhat dilated behind, closely 
and coarsely punctured, with a very distinct smooth longitudinal 
channel ; elytra with a yellowish-grey spot at scutellum, which is some- 
times plain and sometimes obsolete, and with distinct punctured strie, 
interstices broader than the strize very closely sculptured; legs black, 
robust and rather long; underside thickly clothed with yellowish-grey 
scales. L. 4-45 mm. 
Male with the pygidium raised longitudinally and the last ventral 
segment terminated by two subdentiform lobes. 
In seed pods of Iris pseudacorus (Yellow Flag); extremely local, but abundant 
