580 GLOSSARY. 



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

 a simple Actinozoon, 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 separate zob'id of a Polyzoon. 



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



POLYPITE. The separate zob'id of a Hydrozoon. 



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

 bers ; applied to the shells of Foraminifera and Cephalopoda. 



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

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



POLYZOARIUM. The dermal system of the colony of a Polyzoon (= Polypidom). 



PORCELLANOUS. Of the texture of porcelain. 



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

 nate the Foraminifera, or the Sponges. 



POST-ANAL. Situated behind the anus. 



POST-CESOPHAGEAL. Situated behind the gullet. 



POST-ORAL. Situated behind the mouth. 



PRjEMAXiLLJE see Intermaxillse. 



, 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. 



PRjE-ossoPHAGEAL. Situated in front of the gullet. 



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

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

 of articulation of the second rib. 



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

 the Elephants. 



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

 of which are hollow or concave in front. 



PROPODIUM (Gr. pro, before ; pous, foot). The anterior part of the foot in 

 Molluscs. 



PROSOBRANCHIATA (Gr. proson, in advance of; bragchia, a gill). A division 

 of Gasteropodous Molluscs in which the gills are situated in advance of the 

 heart. 



PROSOMA (Gr. pro, before ; soma, body). The anterior part of the body. 



PROTHORAX (Gr. pro ; and t/iorax, chest). The anterior ring of the thorax of 

 insects. 



PROTOPHYTA (Gr. protos ; and phuton, plant). The lowest division of plants. 



PROTOPLASM (Gr. protos; and plasso, I mould). The elementary basis of or- 

 ganised tissues. Sometimes used synonymously for the "sarcode" of the 

 Protozoa. 



PROTOPODITE (Gr. protos, first ; and pous, foot). The basal segment of the 

 typical limb of a Crustacean. 



PROTOZOA (Gr. protos ; and zoon, animal). The lowest division of the animal 

 kingdom. 



PROXIMAL (Lat. proximus, next). The slowly-growing, comparatively-fixed 

 extremity of a limb or of an organism. 



PSEUDOPODIA (Gr. pseudos, falsity ; and poiis, foot). The extensions of the 

 body-substance which are put forth by the Rhizopoda at will, and which 

 serve for locomotion and prehension. 



PTEROPODA (Gr. pteron, wing ; and pous, foot). A class of the Mollusca which 

 swim by means of fins attached near the head. 



PTEROSAURIA (Gr. pteron, wing ; saura, lizard). An extinct order of Reptiles. 



PUBIS (Lat. pubes, hair). The share-bone ; one of the bones which enter into 

 the composition of the pelvic arch of Vertebrates. 



PULMOGASTEROPODA (= Pulmonifera). 



PULMONARIA. A division of Arachnida which breathe by means of pulmo- 

 nary sacs. 



PULMONIFERA (Lat. pulmo, a lung ; and/m>, I carry). The division of Mol- 

 lusca which breathe by means of a pulmonary chamber. 



