286 BULLETIN : MUSEUxM OF COMPARATIVE ZOOLOGY. 



except for lines of growth, bordered in front by an inconspicuous angular 

 shoulder ; from this shoulder extend (on the last whorl about eighteen) feeble, nar- 

 row, subequal, protractive, axial riblets, with subequal interspaces, crossed by fine, 

 close-set spiral threads ; the ribs extend to the suture, or on the last whorl to the 

 base, and the threads cover the whole surface ; anal sulcus shallow, outer lip 

 thin, simple, moderately arcuate ; pillar and body smooth, the former obliquely 

 attenuated in front, not pervious ; canal short, wide, slightly recurved ; Lon. of 

 shell, 4.9 ; of aperture, 2.6 ; of last whorl, 3.7 ; max. diam. 2.0 mm. 



U. S. S. "Albatross," station 3418, off Acapulco, iu 660 fathoms, sand, bottom 

 temperature 39°F. U. S. N. Mus. 123,118. 



Mangilia cetolaca Dall, n. sp. 



Aesopus oldroydi Arnold, Mem. CaL Acad. Sci., 1903, 3, p. 238, pi. 6. fig. 7. Not 

 Mangilia oldroydi Arnold, op. cit. p. 213. 



Lower Pleistocene of San Pedro, California, Arnold. 



Living at U. S. S. " Albatross," station 2835, at Ballenas Lagoon, Lower 

 California (N. Lat. 26° 42' 30" ), in five and a half fathoms, temperature 56°P. 



Mangilia enora Dall, n. sp. 



Plate 4, figure 6. 



Shell small, yellowish-white, decollate with about six whorls beside the (lost) 

 nucleus, the spire longer than the aperture; suture distinct, not appresscd, with 

 a broad anal fasciole iu front of it, arcuately sculptured by lunate wrinkles follow- 

 ing the lines of growth and iu the earlier whorls elevated into sharp wrinkles at 

 regular intervals, which are carried more or less distinctly over the anterior part 

 of the whorls ; in front of the somewhat concave fasciole the whorls are rounded 

 and spirally sculptured with numerous close, very fine, sharp, spiral threads which 

 cover the whorl, becoming coarser, less regular, and less crowded toward the 

 canal ; aperture short, lunate ; outer lip with a broad, deep, rounded, anal sulcus 

 close to the suture, the lip in front of it thin, sharp, and strongly arcuately pro- 

 tractive ; body smooth ; pillar very short, smooth, obliquely truncate ; the canal 

 very short, deep, recurved, forming a marked siphonal fasciole; operculum ab- 

 sent. Lon. of shell, 9.5; of last whorl, 5.7; of aperture, 4.0; max. diam. 

 4.2 mm. 



U. S. S. "Albatross," station 3376, off the coast of Ecuador, in 1132 fathoms, 

 ooze, bottom temperature SB".* F. U. S. N. Mus. 123,121. 



Mangilia ? genilda Dall, n. ep. 



I'late 13, figure 3. 



Shell small, white, with aboiit six whorls exclusive of the (lost) nucleus ; suture 

 distinct, the whorl iu front of it slightly turgid, iu front of which the anal fasciole 



