OF PHILADELPHIA. 129 



Hydrophilus atcr ? Melsh. Catal. 



Body elongate-oval, black, tinged with olivaceous : head with 

 two diverging frontal series of impressed punctures; punctures 

 before the eyes and on the orbits : antennjc, palpi and suture of 

 the clypeus yellowish : thorax with a few punctures each side, 

 and an abbreviated oblique series of punctures each side before 

 the middle : elytra, each with four series of punctures, the ex- 

 terior one double : beneath black: pectus with very short dense 

 yellowish hair before; a bitid prominence for the reception of the 

 anterior tip of the sternum : postpectus covered by short dense 

 yellowish hair: sternum grooved before, rounded at the anterior 

 tip, and elongated, subulate, perfectly rectilinear behind : abdo- 

 men glabrous, with a triangular marginal spot of short yellowish 

 hair on each segment. 



Length from one and one-fifth to one and two-fifths of an inch. 



I think this a different species from the 11. ater of Oliv., inas- 

 much as no notice is taken, in the description of that insect, of 

 lateral ventral triangles which are so conspicuous in our speci- 

 mens. It is also a more elongated insect than Ulivior's figure 

 represents the afcr to be; in this respect approaching [201] much 

 nearer to his figure of oblun</its, which, however, is said to have 

 ferruginous thighs, and a but slightly canaliculated sternum. 



In a certain light, the elytra appear, under a lens, to be marked 

 by seven or eight capillary reddish lines. It is rather rare in 

 Pennsylvania, but I obtained several specimens near the llocky 

 Mountains. 



2. H. OBTUSATUS. — Black, convex, rounded behind; sternum 

 with a slight prominence at the anterior tip. 



Inhabits the United States. 



Jfi/th-ophi/us carabaeoides Melsh. Catal. 



Body oblong-oval, convex, black : head, a lunate indented line of 

 confluent punctures before the eyes on each side; orbits punctured : 

 palpi and base of the antennaj, dark rufous: thorax with a very 

 much abbreviated line of impressed punctures each side before the 

 middle, and a few lateral punctures: elytra very obtusely rounded 

 behind; four series of punctures furnishing minute hairs, the outer 

 onedouble: beneath sericeous, with minute yellowish hairs: pectus, 

 prominence not bifid; sternum narrow and nut {•aiialiculate before, 

 1823.] 9 



