110 FOSSIL ASTEROIDEA. 



G-oniaster marginatum, Bghss, 1845 — G. ' Verstein. boh in. Kreideform.,' p. 58, 



pi. 43, figs. 21—32. 



The illustrations of the isolated ossicles described as this species bear strong 

 resemblance to those of M. ParMnsoni. 



Goniaster mammillata, Gabb, described by Clark, 1892, in 'Bull. U.S. Geological 



Survey,' no. 97, p. 32. 



" Determinative Characters. — Body pentagonal, provided with a dorsal and a 

 ventral row of marginal plates that are narrower than high, and distinctly tumid 

 on their outer surface. Only detached marginal plates preserved." 



Remarks. — The isolated plates undoubtedly belong to a species of Pycinaster 

 and bear a strong resemblance to those of Pycinaster angiistatus. 



" Locality and Geological Position. — Yellow Limestone of the middle marl bed 

 of the Cretaceous from Vincentown, New Jersey." 



Pentaceros dilatatus, 8. Marnier, 1906. ' Le Naturaliste,' (2), vol. xx, p. 117. 



The specimen described under this name is an external cast in flint, of which 

 a plaster cast has been presented to the British Museum (Nat. Hist.), E. 13075. 

 Owing to the courtesy of Professor Stanislas Meunier I have been able to examine 

 the original specimen. It shows a well-preserved impression of the abactinal 

 surface. The ossicles of the disc are rhomboidal or hexagonal, contiguous, of 

 almost uniform size, about 2 mm. in diameter. The specimen, therefore, cannot 

 be placed in the genus Pentaceros, and its appearance, measurements, and type 

 of ornament enable me to ascribe it to Pentagonaster obtusus. 



Ophioglypha bridgerensis, Meek, described and figured by Clad; 1892. ' Bull. 



U.S. Geological Survey,' no. 97, p. 29. 



' Determinative Characters. — Disc composed of numerous small imbricating 

 plates. Upper arm-plates wider than long, the outer angles sharp and expanding 

 between the side arm-plates, which are slightly smaller. Under arm-plates long 

 and nearly rectangular in shape. 



