190 DEVONIAN FAUNA. 



1. Hexacrinus interscapulars, Phillips, sp. PI. XXI, figs. 1 — 4 ; and PI. XXII, 



figs. 1 — 2 a. 



1841. Platycrinus intebscaptjlabis, Phillips. Pal. Foss.,p. 28, pi. xiv, fig. 39. 

 1843. — — Austin. Ann. Mag. Nat. Hist., vol. x, 



p. 109. 

 1813. Hexacrinus melo, Austin. Recent and Possil Crinoids, p. 48, pi. vi, 



figs. 1 a — e. 

 1843. depeessus, Austin. Ibid., p. 49, pi. vi, figs. 2 a — e. 



1881. — interscapttlabis, Waclismutli and Springer. Proc. Acad. 



N. S. Philad.,p. 254. 

 1S89. — — Whidborne. Geol. Mag., dec. 3, vol. vi, 



p. 79. 



Description. — Dorsal cup sometimes very large, short, globose, transversely 

 oval -with diameter about 6'5. Attachment of column very small. Basal circlet 

 rather large, very flatly cup-shaped, hexagonal, wider than broad, composed of 

 three large subequal hexagonal basals (one of which is sometimes smaller than the 

 others). Radials five, very large, flat, and perpendicular, resting on five of the 

 six sides of the basal circlet, frequently wider than high, rather unequal in size 

 and shape, roughly hexagonal, straight below, excavate above. Anal plate resting 

 on the two basals, pentagonal, rather higher than wide, and nearly equal in size to 

 the adjacent radials. Arms set horizontally, dividing into pairs almost imme- 

 diately, rounded and with narrow brachials. First primibrachs very small, 

 triangular, fitting into but not filling the excavations in the radials. Second 

 primibrachs very small and linear. Third primibrachs equally small, axillary. 



Tegmen capacious, sometimes flattish, sometimes almost as convex as the dorsal 

 cup, composed of numerous polyhedral plates. 



Ornamentation of plates minute, consisting of crowded little close-set warts or 

 tubercles, connected with each other by four or five minute rays and usually 

 irregularly scattered over the whole surface, but sometimes having a tendency to 

 run into a concentric or a radiating order or sometimes vanishing on portions of 

 I lie surface. 



Size of Calyx. — The type specimen is 45 mm. in height, 45 mm. in breadth, and 

 35 in width. Mr. Vicary's largest specimen is about 55 mm. in height, 55 mm. 

 in breadth, and 45 mm. in width. 



Localities. — This is by far the commonest Crinoid of these beds. From 

 Wolborough there arc eighteen specimens in Mr. Vicary's collection, fifteen in the 

 Torquay Museum, several in the British Museum, nine in the Museum of 

 Practical Geology, one in Mi-. Champernowne's Collection, and one in mine. From 

 Lummaton there arc eleven specimens in my Collection, and probably ten in the 

 Torquay Museum. 



