GLOSSARY. 8 II 



PODOSOMATA (Gr. pous, foot ; soma, body). An order of Arachnida. 

 POEPHAGA (Gr. poe, grass, phago, I eat). A group of the Marsupials. 



POLLEX (Lat. the thumb). The innermost of the five normal digits of the 

 anterior limb of the higher Vertebrates. In man, the thumb. 



POLYCHJ3TA (Gr. polus, many; chaite, bristle). A name often applied to. the 

 Tubicolar and Errant Annelides to distinguish them collectively from the 

 Oligochceta (Earthworms, &c.). 



POLYCYSTIXA (Gr. polus, many ; and kustis, a cyst). An order of Protoza, 

 with foraminated siliceous shells. 



POLYGASTRICA (Gr. polus ; and gaster, stomach). The name applied by 

 Ehrenberg to the Infusoria, under the belief that they possessed many 

 stomachs. 



POLYP ABY. The hard chitinous covering secreted by many of the Hydrozoa. 



POLYPE (Gr. polus, many ; pous, foot). Kestricted to the single individual of 

 a simple Actinozob'n, such as a Sea-anemone, or to the separate zooids of a 

 compound Actinozoon. Often applied indiscriminately to any of the Ccelen- 

 terata, or even to the Polyzoa. 



POLYPIDE. The sepai-ate zooid of a Polyzob'n. 



POLYPIDOM. The dermal system of a colony of a Hydrozoon or Polyzoon. 



POLTPITE. The separate zooid of a Hydrozoon. 



POLYSTOME (Gr. polus, many ; and stoma, mouth). Having many mouths ; 

 applied to the Acinetae amongst the Protozoa. 



POLYTHALAMOUS (Gr. polus ; and thalamos, chamber). Having many cham- 

 bers ; applied to the shells of Foraminifera, and Cephalopoda. 



POLYTROCHAL (Gr. polus, many ; trochos, wheel). An epithet applied to those 

 larvae of Annelides and other Invertebrates, in which there are successively- 

 disposed circlets of cilia. 



POLYZOA (Gr. poluj; and zoon, animal). A division of the MoUuscoida, com- 

 prising compound animals, such as the Sea-mat. Sometimes called Bryozoa. 



POLYZOARIUM. The dermal system of the colony of a Polyzoon (= Polypi- 

 dom). 



PORCELLANOUS. Of the texture of porcelain. 



PORIFERA (Lat. porus, a pore ; and fero, I carry). Sometimes used to desig- 

 nate the Foraminifera, or the Sponges. 



POST- ABDOMEN. That portion of the "abdomen" of Crustacea, Arachnida, 

 and Myriapoda which lies behind the segments corresponding with the 

 abdomen of Insects. 



POST-ANAL. Situated behind the anus. 



POST-GESOPHAGEAL. Situated behind the gullet. 



POST-ORAL. Situated behind the mouth. 



PR^-MAXILLJE. (See Intermaxillae. ) 



PR.EMOLARS (Lat. prce, before ; molares, the grinders). The molar teeth of 

 Mammals which succeed the molars of the milk-set of teeth. In man, the 

 bicuspid teeth. 



PR.E-CESOPHAGEAL. Situated in front of the gullet. 



PR^E-STERNUM. The anterior portion of the breast-bone, corresponding with 

 the manubrium sterni of human anatomy, and extending as far as the point 

 of articulation of the second rib. 



PRESSIROSTRES (Lat. pressus, compressed; rostrum, beak). A group of the 

 Grallatorial Birds. 



PROBOSCIDEA (Lat. proboscis, the snout). The order of Mammals comprising 

 the Elephants. 



PROBOSCIS (Lat. or Gr. the snout). Applied to the spiral trunk of Lepidop- 

 terous Insects, to the projecting mouth of certain Crinoids, and to the cen- 

 tral polypite in the Medusw. 



PROCCELOUS (Gr. pro, before ; koilos, hollow). Applied to vertebrae, the bodies 

 of which are hollow or concave in front. 



PROGLOTTIS (Gr. for the tip of the tongue). The generative segment or joint 

 of a Tape-worm. 



PRO-LEGS. The false abdominal feet of Caterpillars. 



PRONATION (Lat. pronus, lying on the face, prone). The act of turning the 

 palm of the hand downwards. 



