110 Mr. D. Sharp's revision of the species 



of the elytra towards the extremity, while in other 

 specimens this additional sculpture is quite absent ; 

 this latter form is usually of darker and less metallic 

 colour. 



26. Hydrophilus glaber (Herbst ?), Lee. 

 Lee, Proc. Ac. Phil., 1855, p. 368. 

 North America ; Haiti. 



In this species the punctuation of the upper surface is 

 quite distinct and evenly distributed, but does not give 

 rise to a dull appearance ; the systematic punctures on 

 the prothorax form a somewhat short line ; the sternal 

 spine is elongate and much curved away from the body, 

 and is rounded beneath, not flattened ; the apical ventral 

 segment bears a very distinct free spine. The epipleural 

 sculpture is coarse and distinct from the base to near the 

 apex. 



It appears to be variable, or there may be more than 

 one species under the name ; the pubescent area of the 

 posterior femur is sometimes quite small, but in other 

 cases is rather more extensive ; the ventral spine also 

 varies somewhat in its development. 



It seems scarcely possibly that this species can be that 

 intended by Herbst in his description of Hydrophilus 

 glaber; he calls his insect " glaberrimus" and repeats 

 that it has the head, thorax, and elytra quite impunctate, 

 whereas the punctuation of the upper surface is in this 

 species quite conspicuous, and more developed than in 

 any other of the genus, except H. mixtus, Lee. 



It appears to be abundant throughout the United States 

 of North America. 



27. Hydrophilus mixtus, Lee. 



Lee, Proc. Ac. Phil., 1855, p. 368. 



North America ; United States ; New York. 



This is extremely closely allied to H. glaber, but the 

 punctuation of the upper surface is much denser, so that 

 the elytra towards the sides and extremity are dull. The 

 pubescent area on the hind femur is larger than in 

 some of the varieties of H. glaber, but other forms of 

 this latter species have the area quite as extensive as in 

 H. mixtus, 



