644 GLOSSARY. 



vascular connection is established in the higher Mammalia between the 



mother and the foetus. 

 Pla-oen'tal. Possessing a placenta, or connected with the placenta. 

 Plao'oid (Gr. plax, a plate ; eidos, form). Applied to the irregular bony 



plates, grains, or spines, which are found in the skin of various fishes 



{Elasmohi^anchii). 

 Pla-gi-os'to-mi (Gr. plagios, transverse ; stoma, mouth). The Sharks and 



Eays, in which the mouth is transverse, and is placed on the under surface 



of the head. 

 Pla-kab'i-da (Gr. plan'e, wandering). A sub-order of the Turbellaria. 

 Plait-ti-oea'da. 

 Plant'i-qkade (Lat. planta, the sole of the foot ; gradior, I walk). Applying 



the sole of the foot to the ground in walking. 

 Plau'ti-la (Lat. planus, fiat). The oval ciliated embryo of certain of the J3^- 



drozoa. 

 Plas'teon. The lower or ventral portion of the bony case of the Chelonians. 

 PiAT-T-EL'm-A (Gr. platus, broad ; and helmms, an intestinal worm). The 



division of Scoleaida comprising the Tape-worms, etc. 

 Plat-y-ehi'ita (Gr. plains, broad ; rMnes, nostrils). A group of the Quadru- 



Tnana. 

 Ple-si-o-sau'eus (Gr. plesiog, near to ; and saurus, lizard). 

 Pleu'ka (Gr. for the side). The serous membrane covering the limg in the 



air-breathing Vertebrates. 

 Plbu'eon (Gr. pleuron, a rib). The lateral extensijons of the shell of Cmstaoea. 

 Plu'te-us (Lat. for a pent-house). The larval form of the Jicldnoidea. 

 Pueu-mat'io (Gr. pneuTna, air). Pilled with air. 

 Pheu-ilat'o-oyst (Gr. pneuma, air; andiasiiSj cyst). The air-sac or float of 



certain of the Oceanic Hydrozoa iPkysophondm). 

 Pned-mat'o-phoke (Gr. pnewma, air ; and^Aero, I carry). The proximal dilata- 

 tion of the coenosaro in the Physophyrida which surrounds the pneumatocjiBt. 

 PuBn-Mo-sKEL'E-TON (Gr. »»eMma/ aa&. sheUtoa, dry). The hard structures 



which are connected with the breathing organs (e. g., the shell of Molluscs). 

 Pod-oph-thal'mata (Gr. pous, foot ; and opnthalrnos, eye). The division of 



Crustacea in which the eyes are borne at the end of long foot-stalks. 

 Pod-o-som'a-ta (Gr. yo!/«, foot : «oma, body). An order of .4racA»Mo. 

 Po-eph'a-ga (Gr. pol, grass ; phago, I eat). A group of the Marsupials. 

 Pois'ees. 

 Pol'lex (Lat. for the thumb). The iimermost of the five normal digits of the 



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

 Pol-y-cys-ti'na (Gr. poms, many ; and hustia, a cyst). An order of Protozoa, 



with foraminated siliceous shells. 

 Po-lyg'a-mous (Gr. polus : and gamos, marriage). 

 Pol-y-gas'tbi-oa (Gr. poms; and gaster, stomach). The name applied by 



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



stomachs. 

 Pol'y-pa-ey (Gr. polus; and pario, I produce). The hard ohitiuous cover- 

 ing secreted by many of the Sydiroeoa. 

 Pol ype (Gr. poms, many ; pous, foot). Ecstrioted to the single individual 



of a simple Aotinoeoon, such as a Sea-anemone^ or to the separate zooids of 



a compound Aetmozoon. Often applied indiscriminately to any of the 



CceUnterata^T even to the Polyzoa. 

 Pol'y-pide. The separate zooid of a Polyeoon. 



Poi-Yp'i-DOM. The dermal system of a colony of a Hydrozo'on, or PolyzoSn. 

 Pol'y-pite. The separate zoSid of a Hydrozoon, 

 Pol'y-stome (Gr. polus, many ; and stoma, mouth). Having many mouths ; 



applied to the Aoinetce among the Protozoa. 

 Pol-y-thal'a-mohs (Gr. polms; and thalamos, chamber). Having many 



chambers : applied to the shells oi Foraminifera and Cephalopoda. 

 Pol-y-zo'a (Gr. polus ; and zo'jn, animal). A division of the Molluaooida, 



comprising compound animals, suoli as the Saa-mat. Sometimes called 



Bryozoa, 



