Trichoptcryijina.] clavicornia. 109 



1. Thorax moderately dilated ; liiiid coxtu iiiodcrattly 

 distaut ; posterior mai'gin of metasteruuiu not 



produced into points Ptertx, Ma/l/i. 



2. Tlioi ax strongly dilated; hind coxjb widely distant, 

 posterior margin of nietasternum produced into 



two sharp points between the coxib ACTiNOPTEiiYX, Malik. 



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



II. Thorax constricted behind. 



i. Elytra short; mesosternum not cariuatc; intermediate 



coxic approximate; colour pale Ptinella, Mots. 



ii. Elytra long ; mesosternum cariuate ; intermediate 



coxiB distant ; colour dark Smicrus, Matlh. 



III. Thorax gradually contracted behind, not constricted. 



i. Elytra long, posterior coxas simple Microptilium, Matth. 



ii. Elytra short, posterior coxa; laminate Nephanes, Thorns. 



PTERVX, J\[atthews. ■ 



This genus comprises one European species wliicli is found rather 

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

 other species have been described from North America. 



P. suturalis, Heer. {mutahilis, Matth. ; bicnJor, 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. f-f mm. 



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

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

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

 rare, under bark of dead fir ; Tay and Moray districts (Sliarp) ; Bidmuto, Fifeshire 

 (Power.) 



ACTINOPTERTTX, Matthews. 



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

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

 having the thorax strongly dilated, and from Trkliojjterijx by having 

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

 sternum is produced into two sharp points between the cox?e ; 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 {m(Alis, Hal. ; dilatirollis, j\Iots. -jViarinum, Mots.). 

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

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



