138 THE NAUTILUS. 



Physa Integra Hald. Ohio R., Coraopolis, I ; Beaver, (j. 



Family LIMN^EID^E. 



Limnaea columella Say. Shenley Park, Pittsburgh, 20 ; Ohio 

 E., Beaver, 1. 



Planorbis trivolvis Say. Ohio R.. Coraopolis, 15. 

 Planorbis bicarinatus Say. Ohio R., Coraopolis, 20. 



Family ANCYLID^. 



Ancylus diapha.nns Hald. Near mouth of Raccoon Creek, 2o ; 

 Allegheny R., G m. Isl., Pittsburgh, 50. 



Ancylus rivularix Say- Beaver R., Wampum, 6; Raccoon Creek, 



Beaver Co., '6. 



o * 



A NEW FTERONOTUS FBOM CALIFORNIA. 



fiY W. H. DALL. 

 Pteronotus Carpenter!, n. sp. 



Shell trialate, reddish brown, with obscure spiral lines of darker 

 brown, the aperture whitish with a darker throat; nucleus brownish, 

 whorls about eight, the last much the largest; suture distinct, ap- 

 pressed, intervarical surface smooth or obscurely spirally striate, the 

 apical whorls with reticulate threading; the last two or three whorls 

 with a single obscure nodulosity on the periphery between the var- 

 ices ; varices continuous up the spire; posterior face of the varices 

 smooth with obscure radial ridges which slightly crenukte the margin, 

 in adolescent shells; but in full grown ones there are about five rather 

 wide, low radial ridges, each of which terminates in a digitation of the 

 margin ; anterior face of the varices with profuse, close-set crenulate 

 imbrications, which in fully grown shells show radial depressions cor- 

 responding to the ridges on the back of the varix; digitations exca- 

 vated in a shal'ow manner anteriorly, tennin iting in somewhat blunt 

 projections, thin and sharp edged ; aperture small, oval, with a con- 

 tinuous, raised, smooth margin without denticulations; canal closed, 

 moderately wide, bent to the right in front, a disused smnller canal 

 bordering its posterior two-thirds on the left. Length of shell 57, 

 of last whorl from the suture, 42; width including varices, 35 ; width 

 of aperture, 9.5; length of aperture, 13 mm. 



Monterey, Gala., F. L. Button ; at station 2908, off Pt ConceptFon, 

 Cala., in 31 fms., sand, U. S. Fish Com.; and at the Farralone islands, 

 Gala., J. S. Arnheiui. This shell recalls P. mucropterus Desh.. of the 

 Antilles, and like it belongs to the section Ptcropurpura Jouss. Young- 

 specimens are more pointed, and with narrower, less digitate varices, 



