ASTROPECTEN. 125 



anibiilacnil bones, with their combs of spatuhitc s[)ines, nflbrd additional evidence that these 

 two Star-fishes appertain to distinct sj)ecics. 



Locality and Strati f/rapJtical Position. — This Star-fish which belonfis to the British 

 ]\Iusenni, was collected from the Forest Marble near IMalmesbnry, by Mr. William J5uy, 

 where it was associated wuth numerous Mollusca, Echinidae, and Crinoida?, appertaining to 

 that formation. 



I dedicate this species to my friend Professor Iluxley, F.R.S., whose numerous 

 contributions to palaeontology and zoology have advanced the progress of these branches 

 of natural science. 



E. — Species from the Kelloioay Bock. 



AsTllOrECXEN CLAWEFORMIS, Wri(jltt. PI. XI. 



AsTEiiiAS ARENicoLA, CharlesicortJi. London Geol. Journ., tab. 17, 1847. 

 AsTKOPECTEN AKENicoLUS, Forhes. ]Meni. of the Geol. Siirv., vol. ii, part 2, p. 477, 1848. 



— — Forhes. In Morris's Catalogue of British Fossils, 2nd ed., 



p. 72, 1854. 



— CLAV^FORMis, Wrigfit. Mongr. of Oolitic Echinoderms, Pal. Soc, p. 428, 



18G0. 



Rays five, convex, contracted at the base, enlarged at the inner third by the breadth 

 of the marginal ossicula, and tapering gently throughout the two outer thirds of their 

 length ; disc small, its proportionate diameter to the body as 2 to 9 ; intermediate angles 

 acute, and much contracted by the bulging of the rays; marginal plates variable in 

 width, transversely elongated, and in general exceeding one third of the ray. Ambu- 

 lacral furrows straight and linear, not participating in the enlargement of the margin, 

 which is entirely owing to the form and development of the border plates. 



Dimensions. — Diameter of the disc from one angle to another, one inch and eight 

 tenths ; diameter of the body, nine inches ; width of a ray near the angle, one inch ; 

 width of a ray at the widest part of its enlargement, one inch and one fifth ; from its 

 maximum width to its worm-like point it gradually tapers. 



Description. — This Star-fish was first figured in the 3rd part, pi. 17, of the 'London 

 Geological Journal,' by Mr. Charlesworth, under the name of Asterias arenicola, Goldf., 

 from the belief that it was identical with that species ; in this opinion Professor Forbes ^ 

 concurred, for we find in his memoir on ' British Fossil Asteriada; ' the following diagnosis 

 of this form under the name Astropecten arenicolics, Goldfuss : 



1 Memoirs of the ' Geoloi^ical Survey,' vol. ii, part 2, p. 477- 



