33 i RHYNCHOPHORA. \_Ceutliorrliyncliina. 



prosternuin very narrow between the anterior 

 coxae. 



A. Rostrum about six times as long as broad, 

 shining in front; sides of thorax without 



tubercles AMA.LTJS, Schonh. 



B. Rostrum short and broad, only two or three 

 times as long as broad ; sides of thorax with 



more or less distinct tubercles. 



a. Tibiae and tarsi furnished sparingly with 

 long Latatory cilia ; third joint of tarsi 



narrow, without distinct lobes EuBRYCHiUS, Thotiis. 



b. Tibiae and tarsi without cilia; third joint of 



tarsi widened and deeply bilobed. 

 a*. Antennae inserted in middle of rostrum ; 



last joint of tarsi elongate LITOD.ACTYLUS, Redt. 



b*. Antennae inserted in front of middle of 



rostrum ; last joint of tarsi not elongate PHTTOBIUS, Schmidt. 



IKONONYCHUS, Sehonherr. 



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 onychiura furnished 

 with a single claw, and the scape of the antennae only half as long as 

 the f uniculus ; they live in the pods of species of Iris. 



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. 



IK. pseudacori, F. Black, slightly glossy, form stout and broad ; 

 head hollowed between the eyes which are large, with a few ferruginous 

 scales at the base of the rostrum ; rostrum moderately long and slender, 

 a little dilated at apex ; antennae 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 stria3, 

 interstices broader than the striae very closely sculptured ; legs black, 

 robust and rather long; underside thickly clothed with yellowish-grey 

 scales. L. 4-4| 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 



