88 FOSSIL ASTEROIDEA. 



The following are placed provisionally in the genus Pentaceros : 



8. PENTACEROS PUNCTATUS, n. sp. PL XXVI, figs. 1, 1 a, 1 b. 



Specific Characters. Body of large size. Marginal series of plates possessing 

 well-developed foraminate pedicellarias. Intermarginalia present. 



Material. The only example of this species is a fragmentary portion of an 

 arm preserved in the British Museum (Natural History) and bearing the 

 registered number B. 2561. 



Description. The body of the starfish must have been of large size. The 

 supero-marginals are in contact in the extremity of the arm, although interspersed 

 granular plates occur. Proximally, at least, radial plates were present. The 

 largest supero-marginal present is 11'2 mm. high and 6'5 mm. long in its widest 

 point. It is of rather irregular shape and possesses two foraminate pedicellariaB. 

 The infero-marginal plates alternate with the supero-marginals. They are of the 

 same height as the supero-marginals but only 5 mm. broad. They are oblong in 

 shape ; the two interior corners of the oblong, however, are cut away, making the 

 ossicles six-sided. The foramina once occupied by the pedicellaria3 are deep and 

 often situated in a depression. From the foramen itself ridges may run out, 

 which probably served for the attachment of muscles. 



The infero-marginal series border only the side of the arm and take but little 

 part in the formation of the ventral surface. 



An intermarginal series of rounded granular plates occurs. 



Locality and Stratigraphical Position. Upper Chalk. 



9. PENTACEROS PISTILLIFERUS, Forbes sp. PI. XXV, fig. 5. 



OBEASTEK PISTILLIFERUS, Forbes, 1848. Mem. Geol. Surv. Great Brit., vol. ii, p. 467. 



Forbes, 1850. In Dixon's Geology and Fossils of the 

 Tertiary and Cretaceous Formations of Sussex, 

 p. 329, pi. xxi, fig. 15. 

 PISTILLIFORMIS, Dujardin et Hupt', 1862. Hist. Nat. Zooph. flchin. (Suites 



a Buff on), p. 389. 



PISTILLIFERUS, Forbes, 1878. In Dixon's Geology of Sussex (new edition, 



Jones), pp. 363, 370, pi. xxi, fig. 15. 



