HEXACRINUS. 197 



PL pentangularis, Phillips (not Miller), and now described under the name 

 H. Vicarii. There seems to be reason for separating them on account of their 

 stouter form, and the smaller comparative length of their basals ; but, until 

 better specimens are discovered, it will be impossible to form any definite con- 

 clusion on the subject. 



6. Hexaorinus Vicarii, Whidbome. Plate XXIII, figs. 4, 4 a, 5, 5 a. 



1811. Platycbinus pentangulaeis ?, Phillips (not Miller nor Austin). Pal. Foss., 



p. 135, pi. lviii, fig. 29**. 

 1889. Hexaceinus Vicaeii, Whidbome. Geol. Mag., dec. 3, vol. vi, p. 79. 



Description. — Dorsal cup large, elongate, pear-shaped, decidedly oval in section, 

 with arching sides. Attachment of column small, oval or circular, apparently 

 with a triangular canal. Basal circlet very large and long, probably nearly half the 

 height of the cup, deeply conical in shape with an hexagonal upper margin ; 

 consisting of three plates which are sometimes very unequal in size, one being 

 much narrower than the rest. Radials (indistinctly seen) apparently five, elon- 

 gate, wider above, and deeply and broadly notched at the upper margins One 

 anal plate, intercalated between the radials, elongate, being nearly twice as 

 long as wide, rather narrower above than below, and convex at the shoulders. 

 Suture-lines slight. Surface crowded with minute irregular pustules. 



Size of an imperfect calyx. — Height 32 mm.; ratio of width to breadth 

 about 5:6. 



Locality. — There are three specimens from Wolborough in the Museum of 

 Practical Geology. 



Remarks. — These fossils seem to be sufficiently distinguished by their very 

 elongate pear-like shape and the great relative length of their basals. They give 

 the impression of not being symmetrical, the perpendicular contours being much 

 more arching- on some sides than others ; but how far this was due to accident 

 cannot be determined in the present very imperfect state of the specimens. 



The species is clearly distinguishable from all the other fossils occurring at 

 Wolborough, except perhaps from H. microglyphicus, which it much resembles. 

 That species differs from it in the very decidedly smaller size of the basals and its 

 stouter shape, but I am not certain that it may prove to be more than a variety 

 of it. 



Having compared a small fragmentary specimen in the Museum of Practical 

 Geology with Phillips's figure, I think there is no doubt that this is the species 

 referred by him to Platycrinus pentangularis, Miller; 1 and, if so, he was correct in 



1 1821, Miller, ' Nat. Hist. Crinoidea,' p. 81, pi. xxix, fig. 1, 1-8. 



