﻿216 DEVONIAN FAUNA. 



Taking the figured specimen as the type, the shell is to be defined by its 

 regular and slowly increasing form, its slight, horizontal curvature, and its small 

 rounded apex facing upwards. Of the accompanying species it perhaps most 

 closely resembles C. Ussheri, but it differs from it by its more elongate form, its 

 more rounded and blunter and more oblique apex, and in its surface-markings. 



Capulus squamosus, Trenkner, as given both by himself and by Clarke, seems 

 so close to this form that they should probably be united under one species. 



12. Capulus tylotus, n. sp. PI. XXI, figs. 9, 9 a, 10, 10 a ; PI. XXII, figs. 1, 1 a, 



2, 2 a, 2b. 



? 1841. Acboculia vetusta, Phillips (pars). Pal. Foss., p. 93, pi. xxxvi, fig. 169 a 



(and c) only. 

 ? 1854. Capulus vetustus, Morris (pars). Cat. Brit. Toss., p. 239. 



Description. — Shell rather large, depressed, narrow, elongate, loosely coiled. 

 Spire large, recurved, consisting of more than a volution, much sunk below the 

 highest plane through the shell, very slightly if at all tending upwards. Apex 

 much recurved, nearly or quite direct. Body-whorl rather short, increasing in a 

 rapidly advancing ratio, much produced below near the mouth so as to form a 

 more or less definite concave " wing," subcircular in section, being almost evenly 

 convex except on the inner side, which is flattened : back convex in horizontal 

 section, with a decreasing curvature, so as to become nearly straight close to the 

 aperture ; inner side concave. Mouth not very large, expanding especially on the 

 inner side and below. Peristome slightly sinuous. Surface marked with irregular, 

 sinuous, transverse growth-lines, and fine, crowded, microscopical striae, crossed 

 by numerous indistinct furrows or folds ; and bearing occasional small low 

 tubercles. 



Size. — Width 26 mm., depth 18 mm., height 24 mm. 



Localities. — From Wolborough there are two specimens in Mr. Vicary's Collec- 

 tion ; and from Lummaton there are seven specimens in my Collection, three in the 

 Woodwardian Museum, two in the British Museum, and one in the Torquay 

 Museum. 



Remarks. — This species is distinguished by its comparatively well-developed 

 and large spire, its generally almost horizontal symmetry, the considerable dis- 

 tance of its apex from the plane through the mouth, the elegant curves formed by 

 the changes in the spiral curvature of its walls except on the back, the expanding 

 mouth, and especially by the tubercles of its surface. 



