BRACHIOPODA. 377 
on a low septal ridge (s); dorsal valve with a prominent septum 
(s) supporting a spoon-shaped central process (v); oral lamella 
long and slender (0). Foramen angular, cardinal process dis- 
tinct (7). fossil, 9 species. Carp.—Permian (Magnesian lime- 
stone.) Germany and England. 
Fig. 177. Internal cast.* Fig. 178. Section. 
PENTAMERUS, Sowerby. 
Etymology, pentameres, 5-partite. 
Synonym, Gypidia (conchydium), Dalman. 
Type, P. Knighti, Pl. XV., Fig. 22. Fig. 179. 
Shell impunctate, ovate, ventricose, with a large incuryed 
beak; valves usually plaited; foramen angular; no area or 
deltidium ; dental plates (d) converging, trough-like, supported 
on a.prominent septum (s); dorsal yalve with two contiguous 
Y. / 
tj: Wer \ 
Yyy Z- 
ty 7 Hh) 
Z Yip = 
Longitudinal. Fig. 179. Transverse section. 
fongitudinal septa (ss) opposed to the plates of the other 
valve. 
Oral lamellze haye been detected by Mr. Salter in P. liratus ; 
* Ventral side of cast, showing the V-shaped cavity of the dental plates, and the 
impressicns of branchial veins, accompanied by arteries (after King), 
