MUSEUM OF COMPARATIVE ZOOLOGY. 119 



incremental irregularities. Base subconic, slightly constricted for the canal; 

 notch wide, squarely cut, rounded at the bottom, not touching the suture, a 

 little deeper than wide ; outer lip arched forward, thin, not lirate within ; 

 inner lip smooth, simple : pillar straight ; canal short, wide, very slightly re- 

 curved, leaving a fasciole behind the pillar which is slightly obliquely trimmed 

 off anteriorly ; aperture long, narrow, shorter than the spire. Max. Ion. of 

 shell, 10.2 ; of last whorl, 6.0; lat. of shell, 4.0 mm. 



Habitat. Station 176, near Dominica, in 391 fms., ooze, temperature 

 43°.5 F. 



The sculpture of this shell is of remarkable elegance ; its general form recalls 

 Genota, but the aperture is rather short for that^group. 



Subgenus PLEUROTOMELLA Verrill. 



Pleurotomella Verrill, Am. Joum. Sci., V. p. 15, Dec, 1872. Type, Pleurotomella 

 Packardi Verrill, /. c. 



This group is blind and without operculum ; the teeth resemble those of Bela. 

 The type has the Sinusigera nucleus, turbinate and beautifully obliquely retic- 

 ulate, dark colored and differing in texture from the succeeding shell. It is 

 short, inflated, and very thin, with a rather deep anal sulcus. It is impossible at 

 present to say whether this assemblage of forms is homogeneous or should bear 

 the name of Pleurotomella. Pending further knowledge of the nomenclature 

 in this family and of the animals which have been referred to this subgenus, 

 it forms a convenient resting place for a number of large archibenthal species 

 having some characters in common. 



'o 



Pleurotomella Packardi Verrill. 



Pleurotomella Packardi Verrill, Am. Joum. Sci., V. p. 15, Dec, 1872; Trans. Conn. 

 Acad., V. x). 453, pi. xliii. fig, 9, pi. lvii. fig. 1 ; VI. p. 265. 



P. Packardi var. formosa Jeffreys. 



Defrancia formosa Jeffreys, P. Z. S. 1883, P. 397, pi. xliv. figs. 9, 9 a, 9 b, 1883; 



Watson, Chall. Gastr., p. 349, 1885. 

 Pleurotomella Saffordi Verrill & Smith, Trans. Conn. Acad., VI. p. 151, pi. xxxi. 



figs. 4, 4 a, 1884. 



P. Packardi var. Benedicti Verrill & Smith. 



Plate XIV. Fig. 4. 



fClathurella cala Watson, Chall. Gastr., p. 361, pi. xxvi. figs. 21 a-c, 1885. 

 Pleurotomella Benedicti Verrill & Smith, Trans. Conn. Acad., VI. p. 148, pi. xxxi. 

 figs. 2, 2 a, 1884. 



Habitat. Station 235, off Bequia, in 1507 fms., ooze, temperature 39° F. 

 The typical form is thin, brown, with a somewhat depressed nucleus. The 



