NO. 1863. M0LLU8KS OF THE GENUS ALVAXIA—BARTSCII. 341 



ALVANIA CARPENTERI Weinkauff. 



Plate 29, fig. 8. 



Rissoa carpenteri Weinkauff, Conch. Cab., p. 192, 1885=Alvania reticulata 

 Carpenter, Ann. Mag. Nat. Hist., ser. 3, vol, 14, 1865, p. 429. Not Rissoa 

 (==Alvama) reticulata Montagu, 1808. 



Shell small, elongate ovate, yellowish white. Nuclear whorls one 

 and one-half, smooth, well rounded. Post-nuclear whorls well rounded ; 

 the first two slightly, slopingly shouldered at the summit, marked by 

 slender, axial ribs, of which 24 occur upon the fii-st, 32 upon the sec- 

 ond, and 34 upon the penultimate turn. In addition to the axial 

 ribs, the whorls are marked by spiral cords which equal the ribs m 

 strength; of these cords, 4 occur upon the first and second turns, the 

 space between the summit and the first cord is considerably wider 

 than that between any of the cords and forms a sloping shoulder. 

 On the penultimate whorl, this space is marked by two additional 

 cords, one of which is at the summit and the other is halfway between 

 tliis and the next cord. The spaces inclosed between the axial ribs 

 and the spiral cords are elongated jjits, which have their long axes 

 parallel to the spiral sculpture m aU cases except the median, where 

 the pits are squarish. Suture strongly chamieled. Periphery of 

 the last whorl marked by a spiral sulcus equal to the one separating 

 the first and second supraperipheral cords. Base moderately long, 

 well rounded, not attenuated anteriorly, marked by 6 equal and 

 equally spaced, spiral cords and very feeble continuations of the axial 

 ribs, which here appear as very slender threads. Aperture broadly 

 oval; posterior angle obtuse; outer lip thin, shomng the external 

 sculpture within; mner lip very strongly curved and slightly re- 

 flected; parietal wall covered with, a moderately strong callus, which 

 renders the peritreme complete. 



The type (Cat. No. 17728, U.S.N.M.) was collected by J. G. Swan 

 at Neah Bay, Washmgton. It has three post-nuclear whorls and 

 measures: Length, 2 mm., diameter, 1.1 mm. 



ALVANIA PEDROANA, new species. 



Plate 29, fig. 4. 



Shell elongate-ovate, milk white. Nuclear whorls two, well round- 

 ed, smooth. Post-nuclear whorls almost flattened, marked by rather 

 strong, vertical, axial ribs, of which 22 occur upon the first and sec- 

 ond, and 25 upon the penultimate turn. In addition to the axial 

 ribs, the whorls are marked by spiral cords which almost equal the 

 axial ribs in strength. Of these cords, 5 occur between the sutures 

 on all the whorls, the first being at the summit. The summit of the 



