﻿HOLOPELLA. 227 



3. Holopella duplisulcata, Whidbome. PI. XVIII, figs. 12 — 14. 



1889. Holopella duplisulcata, Whidbome. Geol. Mag., dec. 3, vol. vi, p. 30. 



Description. — Shell small, elongate, spiral, of many volutions. Sutural angle 

 small. Suture rather deep. "Whorls narrow, convex. Surface ornamented by 

 fine, rounded threads, just visible to the naked eye, crossing the whorl in a rather 

 oblique direction, rather concave to the aperture, between each of which upon the 

 lower whorls are several still finer microscopic striae. Body-whorl small, 

 sloping gently in to the base of the shell. Aperture ovate, pointed above, regu- 

 larly rounded below. Outer lip arched, apparently somewhat excavate. Shell- 

 structure thin. 



Size. — About 26 mm. in height, 13 mm. in diameter. 



Locality. — There is a beautiful specimen in Mr. Champernowne's Collection 

 from Wolborough ; two fragmentary specimens in my Collection from Lummaton ; 

 and another specimen, with obliterated surface, in Mr. Vicary's Collection from 

 Chudleigh. 



Remarks. — This species is distinguished chiefly by the possession of a series of 

 fine minor striae in addition to the major. In general shape it approaches very 

 close to Holopella costata, Goldf. sp., 1 from which it chiefly differs in the possession 

 of these minor markings and in its ornamentation being decidedly finer than that 

 of the German shell, though not than that of its English variety. That species, 

 however, is identified by Sanclberger with Terebra Hennahiana, Sow., 2 which is 

 widely separated from the present form by the broadness of its whorls, and the 

 coarseness and directness of its striae. 



Affinities. — Our shell differs from all the others that accompany it except 

 H. costata by its shorter shape and narrower whorls. It is also distinguished 

 from H. tenuireticidata and H. tenuisulcata by the comparative coarseness of its 

 striae. 



As given by their describer, H. tenuicostata, Sanclberger, 3 and II. tenuisulcata, 

 Sandberger, 4 differ from it in having broader whorls and finer striae, and 

 H. piligera, Sandberger, 5 differs in being of a more slender shape, and in having 

 more indistinct markings. Loxonema linctwm, Ph., 6 is quite a different-shaped shell, 

 being very much shorter, and its ornamentation is more regular. 



1 1853, Sandberger, ' Verst. Khein. Nassau,' p. 230, pi. xxvi, figs. 11, 11 a. 



2 1840, J. Sowerby, ' Geol. Trans.,' ser. 2, vol. v, pt. 3, pi. lvii, fig. 22; and 1841, Phillips, ' Pal. 

 Foss.,' p. 99, pi. xxxviii, fig. 184. 



3 1853, Sandberger, ' Verst. Rhein. Nassau,' p. 227, pi. xxvi, figs. 7, 7 a. 

 * Ibid., p. 228, pi. xxvi, figs. 8, 8 a. 



5 Ibid., p. 228, pi. xxvi, figs. 9, 9 a — c. 



6 1841, Phillips, ' Pal. Fobs.,' p. 100, pi. xxxviii, figs. 185 a, b. 



30 



