228 DEVONIAN FAUNA. 



3. POTERIOCRINUS, sp. Plate XXXY, figs. 45 a, and Plate XXXVI, figs. 9, 9 a. 



Description. Large. Stem angular near dorsal cup. Columnars short, alter- 

 nating. Proximal columnar curvilinear. Dorsal cup rather high, conical. Infra- 

 basals five, pentagonal, wider than high. Basals five. Radials rather shorter 

 than basals, with truncated upper sides. Primibrachs 5 X 2 or 3. Arms stout, 

 uniserial, occasionally bifurcating, and composed of truncated cuneate plates, 

 which in the lower parts (at least) bear stout short pinnules or armlets. Anal 

 plates ? Ventral sac extremely large, cylindrical, elongated, with longitudinal 

 undulations, and composed of exceedingly short transverse pieces with long linear 

 slits. 



Size. A dorsal cup is about 12 mm. high. The sac of another specimen is 

 100 mm. high. 



Localities. In the Museum of Practical Geology is a specimen on two slabs as 

 well as two detached ventral sacs from Braunton Down, and another P from 

 Braunton ; in the Woodwardian Museum is a specimen from Barnstaple ; and in 

 the Porter Collection a ventral sac from Pilton. 



Remarks. I first supposed these might be large specimens of Poteriocrinus 

 tensus ; but, though the specimens are imperfect, they reveal several points of differ- 

 ence, e. g. the character of the ventral sac is very different, the arm-plates seem 

 shorter, and the arms more rapidly branching. A pinnule or armlet very near 

 the cup (PL XXXV, fig. 5 a) is noteworthy, as it has the appearance of bearing 

 shorter pinnules on its side ; its true character is therefore obscure. 



2. Genus SCAPHIOOEINUS, Hall, 1858. 



S. dichotomus is the second of the two species described by Hall 1 in 1858 ; but 

 Wachsmuth and Springer select it as the type of the genus as revised by them, 

 because, they state, the first species belongs to the genus Graphiocrinus, de 

 Koninck and le Hon, 1853. 



1. SOAPHIOCEINUS ? PLUMIFER, n. sp. Plate XXXI, figs. 4 4c; Plate XXXIII, 



fig. 1; Plate XXXVI, figs. 1, 1 a-; and 

 Plate XXXVIII, fig. 2. 



Description. Stem becoming acutely pentagonal near the base of the cup, 

 composed of short columnars in a doubly alternating series, having convex peri- 



1 1858, Hall, Keport Geol. Surv. Iowa,' vol. i, pt. 2, p. 553, woodcut 72. 



