216 PATELLA. 



PARACEPH ALOPHORA. Bl. The second class of the type Ma- 

 lacozoa, Bl. divided into the sub-classes : P. dioica, P. monoica, 

 P. kermaphrodita. 



PARIES. (A wall,) Tke principal part of a multivalve shell, 

 forming a circular wall round the body of tke animal, and com- 

 posed of one or more valves which are called the parietal 

 valves. 



PARIETAL VALVES. The principal valves of multivalve shells 

 Burrounding the body like a wall ; as distinguished from the 

 opercular valves, or those which compose the operculum. 



PARMACELLA. Cuv. (A little cell.) Fam. Limacinea, Lam. 

 and Bl. — Descr, Haliotoid, internal, thin ; spire flat, consisting 

 of one or two rapidly increasing whorls ; aperture as large as the 

 whole shell, with the dorsal margins inflected. — Obs. This de- 

 scription applies to Parmacella of Guvier. The shell figured in 

 Sowerby's Genera under that name is Cryptella of Webb. Fig. 

 257, P. Olivieri. Fig. 258, P. Pallidum. 



PARMOPHORUS. Bl. A genus composed of Emarginula elon- 

 gata, Auct. and other species of a similarly elongated form. Aus- 

 tralian. Fig. 242. P. elongatus. 



PARTULA. Fer. Fam. Colimacea, Lam. Auriculacea, Fer. — 

 Descr. Conical, smooth ; spire equal to the aperture in length, 

 consisting of few whorls ; aperture auriform ; outer lip reflected, 

 broad ; inner lip reflected, with a slight prominence on the colu- 

 mella. P. austrahs, fig. 302. 



PASITHiEA. Lea. A genus formed of some pyramidal shells, 

 described as resembling Melania, but separated from that genus 

 on account of being marine fossils. Fig. 317, P. striata. 



PATELLA. Auct. {A dish or platter.) Fam. Phyllidiana, Lam. 

 Retifera, BL— -Descr. Symmetrical, compresso-conical, nearly 

 regular, oblong or oval ; apex sub-central, inclining towards the 

 anterior margin ; aperture oval, forming the base of the shell ; 

 internal surface smooth ; with a muscular impression shaped like 

 a horse-shoe, with the ends bending forwards, encircling and 

 dividing the space all round, except where the interruption occurs 



