368 [June, 



flavis, illarum clava, femorumque ba>i piceis, sterno punctulato, postice subtiliter 

 canaliculate Long. -35 -37. 



San Francisco and San Diego. The fine punctuation is more distinct than in 

 the next, with which this species agrees in the form of body and sculpture of the 

 sternum ; the latter in immature specimens is yellow. 



6. H. s u b 1 ae v i s, elongato-ovalis antrorsum magis angustatus, convexus ater 

 aenescens nitidus, omnium subtilissime punctulatus, antennis palpis pedibusque 

 flavis, illarum clava femorumque basi piceo-nigris, sterno haud sulcato subtiliter 

 punctulato. Loner./ -38 '42. 



Nebraska and Georgia. Differs from the next by the longer form of body, and 

 by the very fine and indistinct punctuation of the upper surface. 



7. H. g 1 ab er, elongato-otalis (mas antice magis, femina utrinque a?qualiter 

 angustatus^; convyxns ater aenescens, nitidus subtiliter punctulatus, antennarum 

 basi palpisque flavis, pedibus nigris flavo-variegatis, sterno sulcato grosse punc- 

 tato. Long. -38 -42. 



Herbst, Kafer, 7, 298 ; tab. 113, fig. 8. 



Lake Superior, New York, Nebraska, Georgia. Differs from the next by the 

 anterior part of the sternal elevation being coarsely punctured, and the punc- 

 tures of the elytra being very fine and equal in size. 



8. H. m i x t u ', elongato-ovalis, convexus, ater aenescens, subtiliter punctu- 

 latus, elytris punctis eubtilibus intermixtis, antennarum basi palpisque flavis, 

 pedibus fiavo-variegatis, sterno antice punctulato, postice sulcato et grosse punc- 

 tato. Long. -35. 



New York, not rare. 



9. H. e 1 li p ti c u s, latiusculus convexus, utrinque obtusus atro-olivaceus, 

 subaenescens nitidus, subtilissime punctulatus, antennis basi palpisque flavis, 

 pedibus (piaecipue anticis) flavo-variegatis, sterno latiusculo ad apicem et postice 

 punctato, postice breviter canaliculato. Long. # 4. 



New Mexico and California. Broader than the others, and equally obtuse 

 before and behind. 



d. 



10. H. s t r i o 1 a t u s, ovalia convexus, nigro-asneus nitidus subtiliter punctu- 

 latus, thorace margine laterali postice latiore flavo, elytris lateribus vittisque 

 angustis pluribus (externa antice cum margine confluente,) antennis palpis pedi- 

 bus sternoque flavis, hoc antice latiusculo grosse punctato, postice laevi canalicu- 

 lato. Long. *37. 



Souther.u States, abundant. The discoidal yellow lines of the elytra are some- 

 times very indistinct. The prosternum is yellow, and the deep groove is not 

 arrested at thfc anterior margin, but divides it, as in H. ovalis. 



Hydrocharis Latr. 



Although Erichson has placed this genus, which corresponds to Hydrophilus 

 Leach, and Hydrous Bridle, Mulsant, as a section of the preceding, it appears to 

 me that the greater size of the prosternum, aad the absence of the metasternal 

 spine ought to be con&idered with the differences in the mandibles as of generic 

 value. With regard to the name to be applied to the genus, if admitted, there 

 is more difficulty. Yet, as the name Hydrophilus, as established by Geoffroy, 

 plainly belongs to the previous genus, and as Leach, in his anxiety to preserve 

 traditions even when superseded by actual publication, applied the name Hy- 

 drous! Linn, to the previous genus, it is obvious that Mr. Brulle acted at least 

 imprudently, in taking the name last mentioned for a genus so closely allied to 

 the original Hydrous, as the one now under consideration. 



It appears, however, from Agassiz' Xomenclator Zoologicus, that the name 

 here ad pled was proposed by Latreille in -1825, (Fam. Nat.), while Mr. 

 Brulle appears to have limited the name Hydrous to this genus in 1834, the date 

 of his "Histoire Nat. des Insectes," and thus to have been anticipated by La- 

 treille. 



