332 RHYNCHOPHORA. [CeutTiorrhyncUna. 



they contract the rostrum and limbs beneath their bodies and fall and 

 remain motionless ; in this condition they are very easily passed over 

 as seeds or little pieces of earth or gravel ; a few, however, have the 

 power of leaping sideways and in this way endeavour to escape ; this 

 property has especially been noticed in Rhinoncus perpendicular is 

 (subfasciatus) and is possessed to a less degree by Rhinoncus Castor and 

 bruchoides, Cceliodes quadrimaculatus, and Ceuthorrhynchus hirtulus. 

 The larvae of the tribe do not differ from the ordinary Rhynchophorous 

 type ; they are whitish, occasionally yellowish, fleshy grubs ; the life 

 history of certain of the species is interesting and will be further re- 

 ferred to. 



As regards the division of the tribe into genera, there is great 

 diversity of opinion ; in the catalogue published in 1883 by the Rev. A. 

 Matthews and myself the following were enumerated as distinct, 

 Mononyclms, Cceliodes, CeuthorrTiynchus, Ceuthorrhynchidius, Amalus, 

 Rhytidosomus, Rhinoncus, Phytobius, Litodactylus, Eubrychius, Tapino- 

 tus and Poophagus ; of these Thomson (Skand. Col. x. pp. 194-197) 

 includes Rhytidosomus under Cceliodes (which latter genus he regards 

 as distinct), and Ceuthorrhynchidius, Tapinotus and Poophagus under 

 Ceuthorrhynchus ; Amalus he considers a separate genus, and the re- 

 mainder he places under Rhinoncus ; the genus Mononychus has always 

 been regarded as distinct, but this does not occur in the Skandinavian 

 fauna. 



Bedel goes considerably further than Thomson and reduces the genera 

 Avhich are found in the basin of the Seine, and which are almost 

 identical with ours, to three only, Amalus, Mononychus and Ceuthor- 

 rhynchus ; of these Mononyclius is distinct, Amahs includes Rhinoncus 

 and its allies, and Ceuthorrhynchus is made up of the species proper, 

 and those belonging to the genera Cceliodes, Ceuthorrhy?ichidius, Rhyti- 

 dosomus, Tapinotiis and Poophagus, and of course to the several sub- 

 genera (such as Stenocarus, Megacetes, Cidnorrhinus, &c.), into which 

 one or two of these have been divided by Thomson and others. 



M. Bedel, in grouping the species together, makes the following re- 

 marks (1. c. p. 162) : " If we pass in review the series of Mediterranean 

 species, we very quickly perceive that the form of the body, the number 

 of joints of the funiculus, the dimensions of the rostrum, the develop- 

 ment of the pectoral channel, the structure of the femora and of the 

 tibiae and their terminating brush of hairs (corbeille) have never the 

 value of generic characters ; they are excellent characters for the dis- 

 tinction of species, but nothing further; " to a very great extent M. 

 Bedel is right, but certain of the characters are in other groups regarded 

 as generic and we are brought back to the old question " What really 

 constitutes a genus 1 " which has never satisfactorily been answered, and 

 certainly cannot be answered as far as the Rhynchophora are concerned 

 in the present state of our knowledge; as, however, the characters which 

 have been given for the various genera belonging to the present tribe 



