Trichopterygina.] CLAVICORNIA. 109 



1. Thorax moderately dilated ; hind coxa; moderately 

 distant ; posterior margin of metastemum not 



produced into points PiERYX, Matth. 



2. Thorax strongly dilated ; hind coxse widely distant, 

 posterior margin of metastemum produced into 



two sharp points between the coxae ACTINOPTERYX, Malth. 



ii. Abdomen with six free ventral segments .... TEICIIOPTEBYX, Kirby. 



II. Thorax constricted behind. 



i. Elytra short; mesosternum not carinate; intermediate 



coxae approximate ; colour pale PTINELLA, Mots. 



ii. Elytra long ; mesosternum carinate ; intermediate 



coxae distant ; colour dark SMICRTJS, Matlh. 



III. Thorax gradually contracted behind, not constricted. 



i. Elytra long, posterior coxae simple MICROPTILLTTM, Matth. 



ii. Elytra short, posterior.coxse laminate NEPHANES, Thorns. 



PTERVX, Matthews. 



This genus comprises one European species which is found rather 

 commonly in many localities under bark and in rotten Avood ; a few 

 other species have been described from North America. 



P. suturalis, Heer. (mutabilis, Matth. ; bicolor, Mots.). Oval, con- 

 vex, rather shiny ; colour very variable, reddish, or castaneous, or with 

 the elytra reddish and the head and thorax almost black, sometimes 

 with the apex of the elytra alone dark ; head rather prominent ; thorax 

 transverse, broadest at base, deeply and very closely tuberculate ; 

 elytra rather remotely asperate, with the apices strongly rounded ; legs 

 and antennae rather long, yellow. L. | |- mm. 



In rotten wood, under bark, sometimes in moss ; not uncommon in some 

 localities, and probably very widely distributed ; Surrey ; New Forest ; Dean Forest ; 

 Midland district, general ; Lincoln (under bark of dead fir) ; Scarborough ; Scotland, 

 rare, under bark of dead fir ; Tay and Moray districts (Sharp) ; B.ilmuto, Fifeshire 

 (Power.) 



ACTINOPTERYX, Matthews. 



This genus was founded by Mr. Matthews to_ include the single 

 species T. fucicola of Allibert ; it is distinguished from Pteryx by 

 having the thorax strongly dilated, and from Tricliopteryx by having 

 seven free ventral segments, and from both by the fact that the meta- 

 stemum is produced into two sharp points between the coxae ; our 

 single species is rather widely distributed on the southern coasts of 

 Europe, and also on the shores of North Africa and the Atlantic 

 islands, but until recently has been considered very rare in Britain. 



A. fucicola, All. (mollis, Hal. dilaticoltis, Mots. ; marinum, Mots.). 

 Fuscous, rather depressed, thickly clothed with short white silky pubes- 

 cence ; head large and broad with prominent eyes; thorax large, strongly 



