BALL: MOLLUSCA AND BRACIIIOPODA. 273 



whorl just behind the periphery; on the fasciole are six or seven smooth rounded 

 subequal spiral threads with equal or wider interspaces, more crowded anteriorly ; 

 beyond the shoulder are nine similar but coarser threads, sometimes entire, some- 

 times flattened or even medially sulcate on top, extending over the base, and on 

 the region of the canal as many more, smaller and more distant, crossed by obvious 

 incremental lines ; aperture elongate, rather narrow, anal sulcus very wide but 

 shallow ; outer lip produced, evenly arcuate to the end of the canal, not constricted 

 at the base of the whorl ; pillar lip smooth, pillar short, obliquely truncate, gyrate, 

 the axis pervious ; canal wide, hardly differentiated. Lon. of shell, 48 ; of last 

 whorl, 35 ; of aperture, 26 ; max. diam. 16.5 mm. 



U. S. S. "Albatross," station 2859, Pacific Ocean, in 1569 fathoms, ooze, bottom 

 temperature 34°.9 F. U. S. N. Mus. 122,563. 



The soft parts and operculum were not obtained, so the shell is only provision- 

 ally placed in this group. It recalls the shell described by rae in tlie Blake Report 

 from Cuba under the name of Aforia hypomela, but which is perhaps an Ireno- 

 syrinx. The latter has the spiral sculpture more delicate, the posterior slope of 

 the whorls flattened, and the whorls more numerous. 



Ancistrosyrinx cedonulli Reeve. 



Pleurotoma cedonulli Reeve, Proc. Zool. Soc, London, 1843, p. 185; Conch. Icon , 

 Pleurotoma, fig. 117 a. 



U. S. S. " Albatross," station 2799, in Panama Bay, in 30 fathoms, mud ; and 

 station 3391, Gulf of Panama, in 153 fathoms, mud, bottom temperature 55°. 8 F. 

 U. S. N. Mus. 123,102. 



Several fairly well preserved specimens were obtained, as above, but without 

 the animal. There is no doubt tliat the species belongs to the same group of 

 Turritidae that iucludes the Atlantic coast A. elegans and A. radiafa Dall, which 

 have granular sculpture and an operculum like Drillia. That Tryon, who knew 

 the Panama species only from an inadequate figure, should have regarded it as tlie 

 young of the Japanese Columbarium (with a wrong locality) was under the cir- 

 cumstances not extraordinary, though erroneous. The relations of this group to 

 Cochlespira Conrad, its Eocene precursor, have already been alluded to (see page 

 257). In view of the ambiguity of Reeve's figure it might be well to say tliat tliis 

 species has no axial sculpture on the wliorls between tiie carina and tlie base ex- 

 cept what may be due to accidents during growth. The surface is normally smooth 

 and polished, above and below the carina, and of a delicate pale brown color. 



Steiraxis aulaca Dall. 



Plate 2, ngure 5. 



Pleurotoma (Steiraxis) aulaca Dnll, Proc. U. S. Nat. Mus., 18iX>, 18, p. 14. 



Shell large, solid, white, fusiform, with about five whorls (nucleus eroded) 

 covered with a pale straw-colored epidermis ; whorls rounded, with rather distinct 



VOL. XLIII. — NO. 6 18 



