Horn.] Id4 [Feb. 21, 



convex and shining. Head and thorax punctured with coarse and fine 

 punctures intermixed. Thorax similar in form to the preceding species 

 and with more traces of the fovea? there seen. Elytra regularly convex, 

 striate, stripe punctured, less deeply on the disc, and strongly at the 

 sides ; intervals flat obsoletely scabrous. Mesosternum slightly promi- 

 nent, prosternum carinate at its posterior half. Body beneath piceous, 

 legs piceo-rufous. Femora at basal half pubescent. Length .30 inch ; 

 7.5 mm. 



Easily known by its broad moderately convex form, from any species 

 in our fauna. 



Occurs at Fort Crook, California, with the preceding. 



H. turn dus, Lee. Proc. Acad. 1855, p. 372. 



A broadly oval very convex species, black and shining, with very slight 

 aeneous tinge. Head and thorax densely and finely punctured. Elytra 

 with strise of moderate punctures between which are fine punctures 

 rather coarser and less dense than those of the thorax. Body beneath 

 and legs black. Mesosternum with prominent crest, acute and slender at 

 its free angle. Prosternum with very faint carina in front of coxrj and at 

 anterior margin an acute elevation. Length .30-.34 inch ; 7.5-8.5 mm. 



Not common in the Middle States. Resembles Philhydrus rotundatus 

 in form, but readily known by the generic characters. The femora are 

 not at all pubescent, the only remaining pubescence being on the trochan- 

 ters. This would seem to indicate that the species should be placed in 

 the sub-genus Puracymus, but the very close relationship between this 

 species and the following forbids their separation. 



H. globosus, Say (IlydropMlus), Long's Exped. II, p. 276; Lee. Proc. 

 Acad. 1855, p. 372. 



Broader than the preceding species and smoother. The surface is 

 similarly punctured but in each part more finely and obsoletely. Meso- 

 sternum with a thick pyramidal crest, broad on its lower face. Proster- 

 num not carinate. Length .30 inch ; 7.5 mm. 



Occurs from the Middle States to Canada and more common than the 

 preceding. The hind thighs have the basal third opaque and punctured, 

 the opacity extending obliquely outwards on the anterior margin. 



H. fuscipes, Linn. (Dytiscus), see Mulsaut. Col. France, Palpic. p 122 ; 

 aeriatun, insculptus, regularis, Lee. Proc. Acad. 1855, p. 372. 



Oblong oval, piceous black, usually with tinge of bronze, surface mod- 

 erately punctured, scarcely less densely on the elytra than thorax. 

 Elytra striate, stria? punctured, the third, fifth and seventh intervals with 

 a row of distantly placed coarser punctures. Length .L8-.34 inch ; 7- 

 8.5 mm. 



This species varies greatly as may be seen by consulting the remarks 

 of Mulsant. The variation extends not only to the superficial characters 

 of sculpture but the usually important mesosternal crest. The crest is 

 usually of moderate size and acute at tip, but the size gradually dimin- 



