36 G CLAVICORNIA. 



rest of the Byrrhiclae it is distinguished by having the head prominent 

 and not retractile, and by the very large mentura which in great measure 

 covers the mouth parts ; the insect is subovate and convex, black and 

 rather shining, with the head and thorax rather minutely but not very 

 thickly punctured ; the elytra are deeply and closely punctured, and are 

 each furnished with five rows of yellowish bunches of setas ; the 

 anterior legs only are retractile ; the length of the insect is 4 mm. ; it 

 occurs under bark and at exuding sap of trees, especially elms and 

 alders; the larva is very peculiar, being broad in front arid much 

 narrowed to apex, with the head and prothorax very large, arid being 

 furnished at the sides of the segments (except prothorax) with setigerous 

 tubercles or papillae ; the colour of the upper surface is dark brown. 

 The genus contains four or five species from Europe, Ceylon, and 

 North America, which are often considered as a separate tribe of the 

 Byrrhidse distinguished by the name Nosodendrina.) 



Seven genera belonging to the family and about sixty species are 

 found in Europe ; of these five genera and eleven species occur in 

 Britain ; this i., however, exclusive of Limnichus and Aspidiphorus, 

 which are now included. The genera may be divided as follows : 



I. Antennae 11-jointed. 



i. Antennae with distinct 3-jointedclub; upper surface with 



strong upright setae SYNCALYPTA, Dillwyn. 



ii. Antennae with joints 7-11 gradually thicker ; upper 

 surface without strong upright setae. 



1. Upper surface not metallic; abdomen with the first 

 ventral segment furnished with distinct fovese for the 

 reception of the posterior legs ; all the tarsi retrac- 

 tile BYRRIIUS, L. 



2. Upper surface metallic ; abdomen with the first 

 ventral segment not furnished with foveae for the re- 

 ception of the posterior legs. 



A. Anterior tarsi only retractile. 



a. Elytra with striae complete to apex CTTILUS, Er. 



b. Elytra without striee MOKYCHDS, Er. 



B. None of the tarsi retractile; elytra with sutural 



stria complete, dorsal striae ceasing before middle . SIMPLOCABIA, Marsh. 



II. Antennae 10-jointed. 



i. Tarsi heteromerous ; abdomen with five free ventral 



segments AsplDiPHORTJS, Latr. 



ii. Tarsi 5-jointed ; abdomen with five ventral segments, 



the first three being connate LIMNICHUS, Latr. 



SYNCALYPTA, Dillwyn. 



About twenty species are contained in this genus, of which eight are 

 found in Europe, and the remainder have been described from North 

 America, the Atlantic Islands, Burmah, &c. ; they are very small black 

 insects, more or less thickly clothed with strong upright setae ; our three 

 British species may be separated as follows: 



