﻿LOXONEMA. 173 



1879. Loxonema sictjla, Hall. Pal. New York, vol. v, pt. 2, p. 43, pi. xxviii, 



figs. 1—3. 

 1882. angulosum, Barrois. Mem. Soc. Geol. Nord, vol. ii, No. 1, 



p. 278, pi. xiii, fig. 5. 



Description. — Shell small, very elongate, subulate, acuminate, of very many 

 whorls. Whorls rather broad, being in height about two-thirds the diameter of 

 the shell at that point ; moderately and evenly convex. Suture simple, shallow. 

 Ornamentation consisting of strong, regular, slightly arched, sharp ridges, 

 concave towards the mouth, their curvature being greatest on the shoulder, and 

 on the whole tending rather forwards from apex to base ; divided by wider 

 furrows ; about twenty or thirty ridges on each whorl. 



Size. — A specimen in the Museum of Practical Geology, consisting of the 

 seven upper whorls, is 18 mm. in length. 



Localities. — There is a specimen from Wolborough in the Museum of Practical 

 Geology, and another from Lummaton in my Collection. A specimen from 

 South Petherwyn is in the Woodwardian Museum. 



Remarks. — This was evidently a very beautiful shell. Its transverse ridges 

 are just visible to the naked eye. They appear to have increased gradually in 

 number as it advanced in age, the new ridges sometimes starting in the centre of 

 the whorl, and thus causing a variation in the amount of arching in the neigh- 

 bourhood. My specimen from Lummatou is very poor and much obscured 

 by the matrix, which may account for the divergency of shape which is seen 

 in it. 



The specimen in the Woodwardian Museum is the smaller of the two shells 

 figured by Sowerby as L. nexile. It evidently differs very widely from his other 

 specimen, which has generally been accepted as the type of that species, and it 

 therefore remains without a name. It consists of two apical whorls in a beautiful 

 state of preservation. 



Sandberger's figure of his Loxonema obliquiarcuatum 1 seems only to differ 

 from the English fossils in being slightly less elongate, and in having slightly 

 more numerous striae bent more forward. I am rather inclined to believe 

 that it may be the same species, but the difference in height prevents me from 

 uniting them decisively at present, or from using Sandberger's name for our 

 English fossils. It is perhaps intermediate between this species and L. nexile. 



Loxonema sicula, Hall, 2 also seems to agree exactly in shape and ornament with 

 the present shell. The only difference discernible, which does not seem of 

 specific importance, is a narrow flat band below the suture in the American shell. 



1 1853, Sandberger, ' Verst. Ehein. Nassau,' p. 231, pi. xxvi, figs. 12, 12a. 



2 1879, Hall, ' Pal. N. T.,' vol. v, pt. 2, p. 43, pi. xxviii, figs. 1—3. 



