﻿HOLOPELLA. 22& 



sutures appear when viewed on one side almost horizontal, and when viewed in 

 the opposite direction exceedingly oblique. The shape of the aperture cannot be 

 properly made out as its lower part is broken away, but there are signs of a strong 

 columella or rounded inner lip. 



Affinities. — In Holopella Hennahiana, Sowerby, the whorls are more convex, 

 the transverse striae coarser, the sutures larger, and there are no spiral threads. 



2. Holopella tenuisulcata, Sandberger. PL XVII, figs. 20, 20 a; and PL XVIII, 



figs. 10, 10 a, 11. 



1853. Holopella tenuisulcata, Sandberger. Verst. Bhein. Nassau, p. 229, 



pi. xxvi, fig. 6. 

 1860. — elongata, Mchwald. Lethaea Eossica, p. 1123, pi. xliii, fig. 9. 



1889. — tenuisulcata, Whidborne. Geol. Mag., dec. 3, vol. vi, p. 30. 



Description. — Shell of moderate size, elongate, spiral, of many whorls. Sutural 

 angle large, probably variable. Suture rather deep. Whorls broad, about two- 

 thirds their diameter in height, numerous, probably eight or nine, moderately 

 convex, becoming suddenly steeper at the lower end, so as slightly to overhang 

 the suture. Ornament consisting of very numerous, fine, transverse, very 

 irregular, subacute striae, which sometimes appear and vanish indiscriminately, 

 and are very unequal in size, and which are reticulated or crenulated by very 

 indistinct and still closer spiral lines, so as to give them the appearance of frills. 

 Base of shell rounding gently in, nearly smooth. Aperture small, broadly ovate, 

 pointed above, rounded below. Columella short, arched, involute at the extremity. 

 Outer lip sharp, moderately convex, slightly expanded along its edge. Shell- 

 structure thin. 



Size. — A specimen consisting of the five lower whorls is 34 mm. high and 14 

 mm. in diameter. 



Locality. — From Wolborough there are two good specimens and a poor cast in 

 Mr. Vicary's Collection ; another, which is very poor, but appears to belong to the 

 same species, in the Museum of Practical Geology, and a cast which is scarcely 

 identifiable, but which is similar in shape, in the Torquay Museum. From 

 Lummaton there is a specimen in the Woodwardian Museum. 



Remarks. — Upon the penultimate whorl of the Woodwardian specimen is a 

 broad band formed by two parallel brown-stained lines. This mark seems rather 

 perplexing, for although it is in a natural position upon the whorl it is hard to say 



