BOURGUETICRINUS. 35 



In Mr. Wetherell's collection are several fragments of the arms and pinnules, but none 

 in a condition sufficiently good to enable us to make out the details of the head. The 

 arm-joints Avere ratlier strong, and equal, rounded dorsally, and smooth. The pinnules 

 were tapering, and about seven times as long as the arms are broad. 



This species has been found abundantly in several localities of the London Clay; as at 

 Hampstead, Hornsey, Copenhagen Fields, Chalk Farm, Sheppey, and Heme Bay. The 

 fragments of stems vary much in degree of rotundity and indications of lobation. Young 

 examples are more distinctly five-lobed than old specimens. 



2. Pentacrinus Sowerbii. {See Woodcut, p. 36.) 



Pentacrixus Sowerbii, Wetherell. Trans. Geol. Soc, London, 2d series, vol. v, p. 132, 



pi. viii, fig. 4. 

 — — Austen. Monog. of Recent and Fossil Crinoidea, p. 123, 



pi. xvi, fig. 3, a audi/. 



Mr. Wetherell found, along mth Pentacrimis swhbasaltiformis, in the London Clay 

 near Highgate, the columns of a Pentacrinite Avith unequal joints, which he rightly 

 regarded as distinct, and has figured under the above name. 



The joints are more strongly angled than in the last ; the angles very much rounded. 

 Mr. Wetherell remarks, that there are two obscure tubercles on each of the larger joints. 

 In one specimen there are two small joints between each large one. The articular surfaces 

 are regularly five-lobed ; the lobes rounded, with acute angles between them. 



3. Pentacrinus Oakeshottianus. {See Woodcut, p. 30.) 



In Mr. Wetherell's extensive collection of Eocene Pentacrinite stems, there are several 

 fragments of columns, which seem to have belonged to a different species from either of 

 the two named kinds, and though small, appear to be distinct from young examples of 

 P. mb-basaJfiformis, which they most nearly resemble. The joints are equal, acutely jient- 

 angular, with a shallow groove between the angles. The articular siu-faces are regularly 

 stellate. In a portion of a column four tenths of an inch in length by one tenth in breadth 

 there are twelve joints. 



The specimens were found near Chalk Farm. 



Genws BouRGUETicRiNUS, ly Orhigny. 



A genus of the Apiocrinite group of Crinoids, having a slender column without ramules, 

 and composed of graduated joints, with their articular surfaces plain, or marked by a trans- 

 verse ridge, but never stellate. The summit of the stem is enlarged and pyriform, though 

 small, and is composed of two sets of pieces. The cup is veiy shallow. 



