SCAPHIOCRINUS. 229 



pheries. Dorsal cup basin-shaped, wider than high. Infra-basals five ? short. 

 Basals five, almost regularly hexagonal in shape, as wide as high. Radials five, 

 wider than high, pentagonal ? convex, and with wide horizontal upper margins. 

 Surface of plates of the cup marked with strong (sometimes intermittent) ridges, 

 radiating from the centres of the basals and other points. Primibrachs five, in 

 from one to six rows, the first, the second, and the sixth primibrachs appearing to 

 be axillary in different arms. Arms elongate, branching two or three times at 

 rather regular distances so as to become about twenty-eight in all. Brachials 

 rugose, uniserial, cuneate, bearing numerous slight, close-set, elongate pinnules of 

 six or eight plates. Ventral sac probably (as seen in another specimen) long and 

 narrow, and composed of small subhexagonal pieces marked with stellate ridges. 

 Anal apparently situated on the horizontal top of a basal, and bearing on its 

 shoulder a second anal, above which seem to be other interambulacral plates. 



Size. A cup with the greatest portion of the arms hitherto found measures 

 about 60 mm. in length. 



Localities. In the Woodwardian Museum are six fine specimens of parts of 

 the dorsal cup and arms from Barnstaple (on seven slabs) ; in the Barnstaple 

 Athenaeum a specimen of the extended head, and another (on two slabs) of the 

 closed head from Braunton ; in the Museum of Practical Geology a specimen from 

 Braunton, and in Mr. Coomara Swamy's Collection one from the Pilton Beds. 



Remarks. It appears to me that these specimens give evidence of a well- 

 marked species, though in spite of the excellence of several of the specimens it 

 seems impossible to be certain about some of its most important characters. 



The elaborate ornamentation of the dorsal cup, and the ridges or rugosities on 

 the larger arm-plates, are of some assistance in identifying the specimens ; but the 

 plates of the cup, and especially the arrangement of the anals, are not well shown 

 in any of the specimens, none of which enable us to trace the plates all round. 

 One of the Woodwardian specimens shows short stout armlets of three segments 

 upon the secundibrachs, which seem, however, only modifications of the pinnules 

 of the higher branches. 



I have found very great difficulty in locating this species in any of the genera 

 allowed by Wachsmuth and Springer. While the ornate surface of its body- 

 plates would approach their definition of their restricted Poteriocrinus, the shape 

 of the dorsal cup is quite different, as also is the arrangement of the primibrachs. 

 While perhaps not quite falling within the limits of their emended definition of 

 Scaphiocrinus, Hall, it certainly bears sufficient likeness to several species referred 

 by them to that genus to be imagined congeneric. 



