ACTINOCRINUS. 221 



three, situated on the level of the second primibrach in the fourth row three 

 which are very small. Anal area (PL V, fig. 21) with in the first row, an aual 

 plate equal to and intercalated between the radials in the second row, three 

 plates arching over the former, and more or less level with the first primibrachs 

 (the two lateral of these being of the same size as the primibrachs, and the central 

 smaller) in the third row four (or five?) smaller plates in the fourth row five 

 smaller plates rather irregularly placed, and above these several more small 

 irregularly placed plates. (The only specimen showing the anal area is, however, 

 too obscure to permit certainty as to the above numbers.) 



Plates of the dome small and bearing central bosses, but in the condition of 

 the specimens not individually decipherable. Arms thickly clothed with long and 

 large, close-set tapering pinnules, having six or seven joints. Ornament of body- 

 plates nodular-radiate. 



Size. A specimen of a portion of a dorsal cup is about 35 mm. across at the 

 base of the arms. 



Localities. In the Museum of Practical Geology are two slabs containing 

 portions of two very large specimens from Braunton, half a calix with stem from 

 Barnstaple, another calix with arms from Barnstaple, and another specimen 

 showing the arms and part of the dome, and another of a calix divided 

 transversely from North Devon. In the Woodwardian Museum are two 

 specimens of the dorsal cup, and two of the arms from Barnstaple. In the 

 Porter Collection is a specimen of the dorsal cup, and two of portions of the arms 

 from Pilton. 



Remarks. Although several of these fossils are much finer as specimens than 

 are often found in the Pilton Beds, none of them show the entire cup, and 

 therefore it is not easy to judge of the value of their individual plates without 

 some uncertainty. The plates of the dorsal cup are ornamented by coarse 

 radiating ridges, and the starting of the arms form clustered projections from the 

 side of the cup, after the manner of typical forms of Actinocrinus, with which 

 genus it appears to agree generally, unless it be in the mode of branching of 

 its arms. 



A curious case of deformity occurs in one of the specimens (PI. XXXI, 

 figs. 1, 1 a, 2). One of its arms, instead of simply bifurcating at the thirteenth joint, 

 divides into three branches at once. These three new arms go off as nearly as 

 possible at the same level ; the regular biserial arrangement of the back of the 

 arm is broken at the beginning of the division by several small plates, mostly 

 pentagonal in shape, but it is at once resumed as soon as the division is 

 completed. 



Another specimen of a dorsal cup in the Porter Collection (PI. V, fig. 21) 

 is interesting as having had its dome covered by a Capulus (Orfhonychia) . 



