KO. 22SS. NEW MOLLUSKS OF THE FAMILY TURRITIDAE—DALL. 51 



subeqiial interspaces, in the space between the periphery and the 

 succeeding suture, and on the hist whorl on the base about twenty 

 flatter spirals with narrower interspaces; most of the threads are 

 swollen wdiere they pass over the ribs; aperture wide and short; 

 anal fasciole deep and rounded, not quite adjacent to the suture; 

 outer lip thin, produced, sharp; body erased; pillar short, gyrate, 

 but the axis not pervious; canal distinct, short slightly recurved. 

 Height of shell, 19; of last whorl, 12; diameter, 8 mm. Cat. No. 

 210544, U.S.N.M. 



Rmige. — Station 4407, off Catalina Island, California, in 600 fath- 

 oms, ooze, U. S. Bureau of Fisheries. 



PLEUROTOMELLA THALASSICA, new species. 

 Plate 3, fig. 4. 



Shell small, snow white, with five or more whorls exclusive of the 

 (lost) nucleus; suture distinct, appressed, the fasciole in front of it 

 constricted, giving the whorls a conspicuous shoulder; spiral sculp- 

 ture of a few obsolete threads on the base, not extending to the canal 

 and with wider interspaces; axial sculpture of (on the penultimate 

 whorl 16) strong obliquely protractive ribs, most prominent at the 

 shoulder where they begin, disappearing on the base and obsolete 

 on the last whorl; the incremental lines are inconspicuous; aperture 

 rather wide, anal sulcus close to the suture, rounded, rather wide but 

 not deep; outer lip thin, much produced; inner lip erased, pillar 

 short, canal short, deep, distinct, recurved, with a distinct siphonal 

 fasciole. Height of shell, 10; of last whorl, 5.5; diameter, 5 mm. 

 Cat. No. 214206, U.S.N.M. 



Range. — Station 3346, off Tillamook Bay, Oregon, in 786 fathoms, 

 mud, bottom temperature 37.3° F. U. S. Bureau of Fisheries. 



PLEUROTOMELLA OCEANIDA, new species. 



Plate 3, fig. 5. 



Shell small, thin, pure white, with five well-rounded whorls with- 

 out the (lost) nucleus; suture distinct, anal fasciole wide, arcuately 

 wrinkled; axial sculpture of (on the last whorl about 30) narrow 

 thread-like ribs extending from the fasciole to the base with wider 

 interspaces; also very fine close incremental lines; spiral sculpture 

 of (on the penultimate whorl five or six) similar threads slightly 

 nodulous where they intersect the ribs, with wider interspaces in 

 each of which is a smaller intercalary thread ; this sculpture extends 

 to the base on the last whorl, the interspaces on the canal have no 

 intercalary thread; aperture rather wide, anal sulcus rounded, deep, 

 outer lip thin, produced, inner lip and pillar erased, the columella 

 gyrate, attenuated in front, the axis pervious, the canal a little 

 recurved. Height of shell, 12; of last whorl, 8.5; diameter 6.7 mm. 

 Cat. No. 123117, U.S.N.M. 



