POLYGONUM. 



233 



Philippine Islands. Fossil species are found in several of the 

 supra-cretaceous beds. Fig. 178, P. gibbosa. 



PNEUMOBRANCHIA. Lam. The second section of the order Gaste- 

 ropoda, Lam. containing the family Limacinea, fig. 256 to 263. 



PODOPS1S. 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. 



POLINICES. Montf. A genus composed of Natica Mammilla, 

 and other similar species, with mammillated spires, and the 

 umbilicus filled with enamel. Fig. 327. 



POLLIA. Gray. Tritonidea, Sw. The name given by Gray 

 was pre-occupied by a genus of Lepidopterous Insects. 



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

 Order. Pedunculated Cirripedes, Lam. — Descr. 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.— Ohs. This description will be found to 

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

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

 genus under the name of Mitellus by some authors, and it is cer- 

 tainly very different from P. polymerus, fig. 37, and P. cornucopia. 



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

 Foraminifera. 



POLYBRANCHIATA. Bl. (IIoXvq, polus, many ; , branchice, 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. 



POLYDONTES. Montf. ( UoXvq, polus, many ; oSoq, odos, tooth.) 

 A species of Helix, shaped like Carocolla, and haying a 

 number of teeth in the aperture. 



POLYGONAL . Many-sided. 



POLYGONUM. Schum. (YLoXvc, polus, many ; yoma, gonia, an 

 angle.) A genus composed of species of Turbinella, Auct. 



