184 CLASS II. BRACHIOPODA. FAMILY 2. ADH^RENTIA. 



in the organization of its inhabitant. The inside of both valves is of a very 

 pale greenish colour, and finely granulated ; the lower valve is convex, 

 but the upper one is flat and curiously indented, as if to fit certain corre- 

 sponding parts in the body of the animal. These indentations, which 

 spread round in semicircular direction from the hinge, look exactly as if 

 they were picked out in wax ; and in a specimen which we have examined 

 with considerable minuteness, they were filled with the dried remains 

 of numerous fine cilia. As the only recent species known is found in the 

 Mediterranean, we hope that Professor Owen, or some other learned ana- 

 tomist, will be able to account for this singular development. 



Examples. 



PL CXXVII. Fig. 1 and 2. (fossil.) 



Thecidium pumilum, Sowerby, Genera of Shells, No. 20. Deshayes, 

 Note in new edit, of Lamarck, vol. vii. p. 348. 



PI. CXXVII. Fig. 3. (fossil.) 



Thecidium digitatum, Sowerby, Genera of Shells, No. 20. Deshayes, 



Note in new edit, of Lamarck, vol. vii. p. 348. 

 Thecidea hieroglyphica ? Defrance. 



PL CXXVII. Fig. 4 and 5. (fossil.) 



Thecidium kecurvirostre, Sowerby, Genera of Shells, No. 20. Des- 

 hayes, Note in new edit, of Lamarck, vol. vii. p. 349. 

 Thecidea curvirostris , Defrance. 



PL CXXVII. Fig. 6 and 7. 



Thecidium Mediterraneum, Defrance, Diet. Sci. Nat., vol. liii. p. 434. 

 Sowerby, Genera of Shells, No. 20. Risso, Prod, de la mer de Nice, 

 t. 4. f. 183. 



