.] LOSQICORNIA. 217 



strong wedge-shap d mandibles, antenna extremely short, 4-jointed ; upper and 

 lower surface of segments usually protected by scuta, nnd, as a rule, furnished itli 

 tubercles which are capable of protrusion and aid locomotion ; legs very short ; 

 tin- lurvaj are usually of a dirty- white colour; they undergo their transformations 

 within tin' trunks of various trees, the eggs being deposited beneath the bark by the 

 fVniMl.'s. which possess a strong corneous ovipositor that is capable of being con- 

 siderably protruded. 



Many of the species have the power of stridulating ; the thorax, 

 where it joins the elytra, is fitted over a sort of short neck before 

 scutellum ; it is on the sides or front of this that the stridulatory organ 

 appears usually to be situated, and the sound is produced by the friction 

 of the inner side of the hinder margin of the thorax against this surface. 

 I have noticed the sound particularly in Agapanthia lineatocollis ; by 

 moving the head up and down, the sound may be produced as loudly in 

 dead specimens that are fresh as in living ones ; in the Prionina 

 certain species produce a sound by rubbing the hind femora against the 

 of the elytra. A number of species have also the faculty of 

 emitting a strong and distinct smell, sometimes agreeable as in Aromia 

 iiwschata, the well known " Musk Beetle," sometimes the reverse as in 

 Aijapantliia lineatueollis, in which it resembles the smothering smell of 

 a raii'lle which has been blown out and left to smoulder; according to 

 Dr. Horn the episterna of the metasternuin is variable, and near its 

 inner hind angle the duct for the scent gland is situated. 



As might be gathered from what has been before said, the number of 

 genera and species found in Europe is very meagre compared with those 

 found in tropical countries, the total only amounting to one hundred 

 gfiit-ra rnd about four hundred and seventy species; of these, no less 

 th:m eighty-six species are contained in the single genus Dorcadion, 

 which in Europe is confined to the southern countries, and is not 

 represented in Britain ; of these, twenty-eight genera, represented by 

 fifty-eight species, are recorded as British, but some five or six of these 

 latter are doubtfully indigenous ; in Scotland only fifteen genera and 

 twenty-three species have hitherto been discovered ; it is obvious, there- 

 fore, that we possess only a few outlying fragments of this lar^o and 

 important group, and that in dealing with our fauna it is use, 

 discuss the classification of the genera, further than just to mention 

 their principal characters. 



The Longicornia may be divided into the three following families : 



I. Prosternum considerably produced in a blunt process behind 

 anterior coxa? ; thorax margined, with the sides armed with spines 



or teeth ; labruin very small, usually connate with clypeus . . PBIOXID.E. 



II. 1'rosternum not or scarcely produced behind anterior coxa?; 

 thorax not margined, with the sides sometimes armed with spines 

 and teeth, but usually simple in our species ; labrum free and 



distinct. 



i. Anterior tibiie not grooved on their inner side CERAMBTCID.E. 



ii. Anterior ti'oia- grooved ohli jiu-ly on their inner side .... 



