Horn.] J-'J^ | Feb. 21, 



Surface with distinct cupreous tinge, shining, thorax and elytra nearly 

 equally punctured. Mesosternum distinctly protuberant, prosternum 

 finely carinate. Body beneath and legs dark rufo-piceous. Length .06- 

 .08 inch ; 1.5-2 mm. 



Middle States and Canada to California and Oregon. 



H. despectus, Lee. New Species, p. 25. 



Closely resembling subcujjreus but smaller and transversely more con- 

 vex. Surface distinctly aeneous, very minutely alutaceous and with 

 minute punctures sparsely placed. Mesosternum with short acute pro- 

 tuberance, prosternum finely carinate. Length .06 inch ; 15 mm. 



Occurs in Pennsylvania and Illinois. 



H. dissimilis, n. sp. 



Oblong, sub-depressed, dark piceo-testaceous, margins paler. Head 

 piceous moderately densely punctulate. Thorax more than twice as 

 wide at base as long, sides feebly arcuate and slightly narrowed to apex, 

 feebly convex, punctured similarly to the head ; color piceous, margins 

 testaceous. Elytra oblong, parallel, feebly convex, with faint rows of 

 punctures more distinct at the sides and apex, between which are 

 fewer punctures, coarser than those of the thorax but less densely placed. 



Body beneath piceous, femora piceous, tibhe piceo-rufous. Mesosternum 

 and prosternum simple. Length .10-.12 inch; 2.5-3 mm. 



Two specimens, San Francisco, California. 



H. suturalis, Lee. (Limnebius), Proc. Acad. 1866, p. 366. 



Oblong oval, piceous black, shining, with very faint bronze tinge. 

 Head and thorax scarcely punctulate except under very high power, sides 

 of thorax testaceous and nearly transparent. Elytra at margins dark 

 piceo-testaceous, surface almost entirely impunctured. Body beneath 

 black, legs rufous. Mesosternum simple, prosternum in front of coxaj 

 not carinate. Length .06-.08 inch ; 1.5-2 mm. 



In this insect, as in most of the species of Hydrobius, the males have the 

 sixth segment slightly visible at tip. In one specimen which I have 

 examined there is an undue prominence of that segment possibly owing 

 to injury, but in no specimen can there be seen any trace of a seventh 

 segment. The species is therefore referred to Hydrobius from which it 

 does not differ. 



Middle States and Canada. 



Limnocharis. Horn. 



L. piceus, Horn. Trans. Am. Ent. Soc. IV, 1872, p. 144. 



Oval, more attenuate behind, piceous, sparsely pubescent. Thorax 

 finely and sparsely punctulate. Elytra finely alutaceous. Body beneath 

 black, densely punctulate, sparsely pubescent. Legs testaceous. Length 

 .06 inch ; 1.5 mm. 



One of the most minute species in our fauna. The eight segments of 

 the abdomen serve at once to distinguish this genus from any one previ- 

 ously known. 



Occurs near Fort Crook, California. 



