BRACHIOPODA. 
117 
Animal : — Mantle extending to the margin of the valves, 
closely adherent ; oral arms elongated, folded upon themselves, 
fringed with long cirri on their outer margins, and supported by 
a complicated shelly loop (fig. 26). 
Craniaceae (part.), Menke, Syn. ed. 1. p. 56, 1828. 
Craniacea (part.), Menke, Syn. ed. 2. p. 96, 1830. 
Craniae (Les Cranies), part., F&uss. Tabl. Syst. p. 38, 1821. 
Thecideidse, Gray, Syn. B. M. 1842, 85. 92. 
Thecidaeidse, King, Permian Fossils, 81. 142. 
Thecidiae, D’Orbigny, Ann. Sci. Nat. 1848. 
Cryptobrachia, Gray, Ann. Nat. Hist. 1848, \di. p. 435. 
Ancylobrachia (part.), Permian Fossils, 81. 142. 
Thecideae (Thecidees), Desk. Ency. Meth. iii. t. , 1836. 
Thecidiodae, Agassiz, Nomen. 1847. 
1. THECIDIUM. 
Char, of Fam. 
Thecidium pumilum. 
Fig. 24. Fig. 25. 
Fig. 24. Dorsal valve :—j. cardinal process. 
Fig. 25. Ventral valve:—/, foramen (closed); d. deltidium; t* teeth; a. ad- 
ductor impressions ; r. retractors ; p, pedicel-muscles. 
