TRICHOPTERYGID^. 



101 



just within the side angles ; prosternal 

 keel simple, narrow ; pubescence long, 

 evident, and semi-raised (except in 

 P. myrmecoj^hilum, Mots.) . 



Sut-genus Ptenidium, 



Mots. 



A. Thorax and elytra coarsely punc- 

 tured with simple deep punctures, the 

 interspaces being minutely punctu- 

 late ; thorax with a broad impvinctate 

 central line ; body black ; antennae and 



legs dark yellow. L. 0-8-0-84: mm. . P. punctatum, Gyll 



B. Thoi-ax not coarsely punctured. 



a, Metasternum smooth, not aluta- 

 ceous. 



a*. Body deep black, clothed with 

 long grey hairs ; head and thorax 

 with distinct, scattered, shallow 

 umbilicate punctures, with a cen- 

 tral impunctate line; elytra with 

 simple punctures, which are either 

 not confluent (type form) or very 

 large, deep and confluent on the 

 apical third (yi\,v.rugos%mi, Britten); 

 antennse dark pitch- brown. L. 

 0-74-0'8 mm 



b*. Body, or at least elytra, castaneous 

 brown, longish, strongly convex ; 

 head and thorax scarcely punc- 

 tured ; elytra with evident punc- 

 tures and very short scattered 

 hair ; antennas yellow. The var. 

 kraatzi, Matth., has the outer 

 basal thoi-acic fovefe deeper than in 

 the type form. L. 0*88-0 -'JG mm. 



P. FUSCICORNE, Ur. 



b. Metasternum alutaceous, at least 

 at the sides. 

 a*. Thorax, especially at sides, almost 

 as strongly punctured as elytra, 

 sides less rounded ; ely ti^a distinctly 

 punctured in eight or nine irre- 

 gular longitudinal rows, furnished 

 with long, semi-erect, grey hairs ; 

 antennae yellow, at most with the 

 last two joints slightly darker. 

 L. 0'90-'94 mm 



P. MYRMECOPHILUM, MotS. 



= formicetorum, Kraatz. 



P. PUSILLUM, Gyll, 

 ajncale, Er. 



