300 KHTNCHOPHORA. [Cossonina. 



the eyes ; the posterior coxae are transverse and ovate ; the femora are 

 unarmed, as is also the cage with Calandra, and the tibiae are usually 

 armed with a strong curved spine at their apical angle. 



The tribe contains a considerable number of genera and species ; 

 these are all, or almost all, wood feeders, and, as observed by M. Bedel, 

 the greater part are found not far from the sea, and two-thirds of the 

 species that have been described belong to insular faunas ; this point 

 has received great attention from Mr. Wollaston, who has described one 

 genus, Microxylobius, containing thirteen species, all of which are 

 peculiar to St. Helena ; in fact the Cossonidae are most interesting as 

 being the archaic remnants of ancient fauna in these detached islands. 



About sixty species are found in Europe, of which nine occur in 

 Britain ; the number of genera assigned to the tribe in the catalogue of 

 Heyden, Reitter and Weise is seventeen, of which six are found in our 

 country ; different authors have, however, arranged the genera in different 

 fashions ; Wollaston, for instance, divided off the genera Brachytemnus 

 and Stereocorynes from Rhyncolus, but they are now again included under 

 it by M. Bedel, who, on the other hand, places our two species Phlceo- 

 phagus ceneopiceus and P. spadix under two distinct genera, Caulotrypis, 

 Woll., and Codiosoma, Bedel, and regards Phloeophagus as including 

 part of the species which are now placed under Rhyncolus. 



I. Scutellntn distinct j metathoracic episterna well 



marked. 



i. Funiculus of antennse 5-jointed PENTAETHEUM, Woll. 



ii. Funiculus of antennae 7-jointed (rarely with 

 6 joints).* 



1. Rostrum terminated by an abrupt trian- 



gular flat dilatation ; anal segment with 

 two small silky hairs on its posterior 

 margin CosSONUS, Clairv. 



2. Rostrum without an abrupt quadrangular 



dilatation at apex ; anal segment without 

 hairs. 



A. Metathoracic episterna rather broad j 

 rostrum very different in the sexes j an- 

 tennse inserted at the base of the rostrum 

 in the male and in front of middle in 



female RHOPALOMESITES, Woll. 



B. Metathoracic episterna linear ; rostrum 



similar in the sexes . RHYNCOLUS, Steph. 



II. Scutellum not visible. 



i. Episterna well marked along the whole length 



of the metasternum ; upper surface glabrous . CATTIOTEYPIS, Woll. 



ii. Episterna indistinct ; upper surface with dis- 

 tinct pale hairs CODIOSOMA, Bedel. 



* Two European species of Rhyncolus, JR. culinaris and R. submuricatusli&ve the 

 funiculus 6 -jointed ; these form the genus Hexarthrum, Wollaston, which ought 

 apparently to be retained. 



