POLTDONTES. 249 



the Lamarckian family Pectenides. Very few species are yet 

 known, they are brought from the Eaat and West Indies and the 

 Philippine Islands. Possil species are found in several of the 

 supra-cretaceous beds. Seven species are enumerated in the 

 Monograph by the Author, Part 8, Thesaurus Conchyliorum. 

 Ex. PI. gibbosa, PI. x. fig. 178. 



PNETJMOBEANCHIA. Lam. The second section of the order 

 G-asteropoda, Lam. containing the family Limacinea, fig. 256 

 to 263. 



PODOPSIS. Lam. This genus appears to have been described 

 from specimens of a species of Spondylus, with the triangular 

 disc broken out, so as to present a similarly shaped foramen, 

 which was supposed to afford a passage for a large byssus. 



POLmiCES. Montfort. 1810. A genus composed of Natica 

 Mammilla, and other similar species, with mammiUated spires, 

 and the umbilicus filled with enamel. PI. xv. fig. 327. , 



POLLIA. Grray, Teitonidea, Sw. The name given by Gray 

 was pre-oecupied by a genus of Lepidopterous Insects. 



POLLICIPES. Leach. (PoUex, a thumb's breadth ; pes, a foot.) 

 Order. Pedunculated Cirripedes, Lam. — Bescr. Conical, com- 

 pressed, consisting of numerous valves, mostly in pairs, three or 

 four pairs forming the principal part of the shell, and surrounded 

 at the base by two or three rows of smaller valves, supported on 

 a scaly, short pedicle. — Obs. This description will be found to 

 exclude ScalpeUum, and Smilium, the valves of which are more 

 equal. The P. MiteUus, Auct. (fig. 37*), has been separated as 

 a genus under the name of MiteUus by some authors, and it is 

 certainly very different from P. polymerus, fig. 37, and P. cornu- 

 copia. PI. ii. fig. 37, 37*. 



POLLONTES. Montf. Miliola, B1. A genus of microscopic 

 Eoraminifera. 



POLTBEANCHIATA. Bl. (HoXvc, polusj many; branchia, 

 gills.) The fifth family of the order Lamellibranchiata, Bl. 

 containing the genera Area, Pectunculus and Nucula, which have 

 a series of small teeth on the hinge. 



POLTDONTES. Montf. Cno\vQ,polus,mmj; ohs,odos, tooth.) 



