﻿182 DEVONIAN FAUNA. 



mens are poor and give few specific marks apart from their general shape, but 

 on the whole they appear to belong to the same species. Mr. Vicary's two 

 specimens were labelled by Salter " Holopella piligera, Sandberger," and to the 

 broader variety of that species they present so close a resemblance that there 

 would be no doubt of their identity were it not that the whorls of our type 

 specimen have the appearance of being perfectly smooth, whereas Sandberger's shell 

 appears to be marked with very fine and indistinct transverse threads. In the basal 

 part of our specimen, however, there are some very faint indications of similar 

 markings, and therefore it appears best to regard it as at most a smooth variety of 

 the German shell. The circular mouth, the strong columella, and the expanded 

 body- whorl seem to be distinctive features ; it is possible, on the other hand, that 

 the bottom of the shell though appearing perfect may be really defective, and 

 that its true termination may be gone. 



Melania prisca, Minister, 1 is a smooth shell which is remarkably similar in 

 general appearance. It chiefly differs in being somewhat more elongate and in 

 having broader whorls. The mouth in Miinster's figure is evidently either defec- 

 tive or misdrawn, and hence it is impossible to say whether the two shells belong 

 to the same genus, but their general appearance would lead to the supposition 

 that they did so ; and, as the specimens which Sandberger figures of his shell vary 

 far more in their elongation and the breadth of their whorls than would cover the 

 distance between the English shell and Miinster's specimens, the only remaining 

 point in question is the smoothness. In that the English shell agrees with 

 Miinster's, and therefore it appears needful to regard them as the same species. 



Affinities. — This shell differs from its accompanying congeners in its slender 

 shape and its smoothness, as well as in the other points just mentioned. Sand- 

 berger remarks that his shell comes very near to, and perhaps may be identical 

 with, Turritella obsoleta and gregaria, Sowerby. These shells from Horeb Chapel 

 are certainly very similar to ours, and are described as smooth; but they 

 are in the form of casts, and it is therefore not very easy to be certain whether 

 they are identical or not. The chief differences appear to be that their whorls are 

 decidedly more convex, and that their shape seems broader. I am, however, very 

 doubtful whether they would prove distinct if the original specimens were 

 compared. Sandberger also compares his species with Melania subangulata, M. 

 deperdita, M. absoluta, and M. antiqua, four badly preserved species, described by 

 Goldfuss 2 in the ' Petref . Germ.,' which, however, all distinctly differ. 



1 1840, Minister, ' Beitr.,' pt. 3, p. 83, pi. xv, fig. 1. 



2 1814, Goldfuss, ' Petref. Germ.,' p. 109, pi. cxcvii, figs. 11—14. 



