210 DEVONIAN FAUNA. 



. A small portion of an arm is 30 mm. long ; another is 10 mm. across. 

 Though the specimens are too fragmentary to convey much idea of the size of the 

 animal, it is clear that it must have been considerably larger than any of the 

 accompanying species. 



Localities. In the Museum of Practical Greology are confused masses of the 

 arms of two animals (in three specimens) from Braunton Down. In the Porter 

 Collection are two fragmentary portions of another animal and a third specimen 

 from Pilton. 



Remarks. Though these specimens are too fragmentary or confused for full 

 description, their very large size, the stoutness of the arms, and the shape and 

 arrangements of the plates, both above and below, show that they belong to a 

 species quite distinct from the other star-fishes of these beds so distinct, indeed, 

 that it must probably be removed from the genus Protaster. The arrangement 

 of the lower side of their rays appears, as far as can be seen, to have much in 

 common with that of Hall's genus Eug aster, but the plates appear not to alternate 

 but to be perfectly level. 



II. Family OPHIUEIM:, Agassiz, 1835. 

 1. Genus OPHIUEELLA, Agassiz, 1835. 

 1. OPHIUKELLA ? GBEGAEIA, Whidborne, sp. Plate XXVIII, fig. 3. 



1896. PEOTASTEE GEEGAEIUS, Whidborne. Proc. Greol. Assoc., vol. xiv, p. 377. 



Description. Animal small, with five very long slight arms, which taper 

 very slowly to a very acute termination. Disc circular? with a finely granulated 

 surface, occupied almost entirely by ten very large, curved, paired, radial plates, 

 which form a prominent petalloid corona. Arms composed of about forty rings of 

 squamose plates in distinctly level rows ; these rows consisting on the dorsal face 

 of a prominent, apparently indented median row, and a row on each side, the 

 plates of which appear to have a triangular depression and to bear a series of 

 four or five small obliquely set comb-like spines. Ambulacral plates large, level, 

 margined by a large circular pore. 



Size. An arm (probably wanting a few terminal joints) is more than 

 25 mm. long. 



Locality. In the Museum of Practical Geology is a slab, containing the 

 remains of numerous specimens, from Braunton Down. 



Remarks. This species is distinguished from the accompanying forms by its 

 prominent corona, the character of its plates, the absence of alternation in the 



