MUSEUM OF COMPARATIVE ZOOLOGY. 51 



Expedition. The British and all the northern specimens, and one Mediterra- 

 nean lot, are of another species, shorter and stouter, which I take to be the gen- 

 uine acuviinata of Jiruj^ibre. It in its turn differs somewhat from the Crag fossil 

 which has been called by the same name, but perhaps not specifically. I have 

 not had access to the work of Nardo or Chiereghini ; but if the name given by 

 the latter, as is probable, was applied to the Adriatic form, it is probably this 

 species, as I have not seen any genuine acuminata from the Adriatic. In that 

 case it would take precedence of the names given by Miss Bush and Morch. 

 I have not seen any specimen of Morch's shell authentically identified, but 

 his comparative remarks render it highly probable that he had the V. oxytata 

 in view. 



The genus Rhizorus of Montfort has been referred to this group, but it seems 

 to be too uncertain to be adopted, and in some particulars would rather recall 

 the Cylichna marmorata of Adams. 



Volvula Bushii n. s. 



This species is stouter, and its posterior process more acutely pointed than 

 in V. acuta ; its posterior end is more inflated and blunt than in V. acuta or 

 acuminata, and the little sharp spine rises more abruptly from this dome. 

 The anterior part of the shell is somewhat narrower than the posterior part, 

 with, very straight sides and columella, toward which it is evenly rounded in 

 front. There is a long chink behind the pillar, a faint wash of callus on the 

 body, and fine microscopic spiral striae over the polished surface. The color 

 is greenish white of a cretaceous quality. The columella is slightly reflected, 

 but not twisted. Lon. 4.6 ; lat. 2.3 mm. 



Habitat. Station 2602,. 36 miles S. \ W. from Cape Hatteras, N. C, in 

 124 fms., sand, bottom temperature 61°.0 F., U. S. Fish Commission. 



Six specimens were obtained. 



Volvula aspinosa n. s. 



Shell white or yellowish, opaque, the young translucent, rather stout, ovate, 

 the aperture as long as the shell, very narrow behind, wider in front, the outer 

 lip sharp-edged, thickened inside, evenly rounded to both extremities, its mid- 

 dle part nearly straight ; the left or opposite side of the shell much more arched 

 than the right side ; surface with well-marked incremental lines, numerous 

 spiral microscopic striae a little stronger toward the extremities; columella 

 thick, short, straight, with a very minute chink behind it covered mostly by 

 callus ; apex dome-like, with a small rising in the centre, which in the most 

 perfect and especially young specimens is pointed ; callus on the body narrow, 

 but well marked. Lon. 4.0 ; lat. 2.0 mm. 



Habitat. Off the North Carolina coast, in 18 to 168 fms,, sand, bottom 

 temperature 61°-75° F., U. S. Fish Commission. Straits of Florida, 150- 

 200 fms., Dr. Rush. 



