1911.] 9 



Joy. The Cat. Col. Eur., 1906, has drlafas, Wehncke, from Sweden, 

 Finland, and North Germany, regardless of the fact that Wehncke 

 (Deutsche Ent. Zeitschr., xxiv, 223, 224, 1880) considered that he was 

 dealing with driafvs, Sharp, from Scotland, which, however, he puts 

 in a section characterised by an even prosternum, whilst the prostemum 

 of our insect is distinctly grooved. Everts (Col. Neerl., i. 111, note) 

 says that striatus, Sharp, and imtnaculatus, G-erh., are synonyms, but 

 as he describes the elytra of the female as entirely smooth it is clear 

 that he did not know our insect. The diagram of the male genitalia 

 of this spec'ies is based on a specimen taken by Dr. Sharp on the shore, 

 Kirkconnell, Dumfries, August 26th, 1868. 



H. wehnckei, Gerh. (immaculatus, Newbery, sec. spec comm.). — 

 To this species belong the specimens from Bury St. Edmimd's on which 

 Mr. Newbery introduced immaculatus, Gerh. It is very common in 

 hill-ponds in the Cotswold district, and I have taken it at Whitwell 

 Common, Felthorpe, and Brundall in Norfolk. There are two speci- 

 mens without locality in Dr. Sharp's collection. Specimens which 

 have not acquired their full colour might be mistaken for fluviaHlis. 

 The diagram of the male genitalia of this species is based on a 

 specimen from Bury St. Edmund's, dissected by Dr. Joy. 



H. immaculatus, Gerh., nee Newbery (I.e.). — I have seen this 

 species from Stony Stratford (D. Sharp) ; Braunton (Champion, Be la 

 Garde) ; Colwall (Tomlin) ; Campbeltown, Isle of Sheppey, Deal (/. /. 

 Walker) ; Sandown, I. W., Lee, Kent (Champion) ; and have taken it 

 near Norwich myself. It is not easy to distinguish with certainty 

 between males of this species and the same sex of wehnchei without 

 reference to the genitalia, but there is a tendency in immacnlatus for 

 the elytral punctures forming the apex of the ninth row to become 

 merged in a black marking ; this tendency is absent in ujehnckei so far 

 as I have observed. This circumstance is not altogether trivial ; by its 

 means I have several times been able to accurately determine before- 

 hand what form of genitalia a given specimen would exhibit. The 

 females, of course, present no difficulty. British specimens agree 

 with a female form from Herr Ganglbauer labelled " immaculutns, 

 Gerh. Type, Liegnitz." 



H. lineatocollis, Marsh. — This ubiquitous species I have taken in 

 streams swift enough to accommodate Brychius elevatus as well as in 

 ponds. In coll. De la Garde there is an entirely pale specimen only 

 25 mm. long. 



