39:) Gl.OSSARY. 



vascular connection is establiskeJ in tlie hi^^her MamniaUa between the 



mother and the I'teUis. 

 Pla-cen'tal. possessing a placenta, or conJiected with the placenta. 

 Plac'oid (Gr. plax^ a plate ; eldos^ form). Applied to the irregular bony 



pUites, grains, or spines, "which are foand in the skin of various fishes 



i^ L'lasmohranchii). 

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



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



of tiie head. 

 Pla-nar'i-da (Gr. _^/a«'', wandering). A suh-order of the Turhellavla. 

 Pl,vn-ti-gra'da. 

 Plant' i-GRADE (Lat. planta, the sole of the foot ; gradlor, T walk). Applying 



the sole of the foot to the ground in walking. 

 Plan'u-la (Lixl. planus^ fiaif. The ov'al ciliated embryo of certain of the Hy- 



dt'Qzoa, 

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

 Plai^y-el'mi-a (Gr. plains^ broad; and helmins^ an intestinal ^\■orm). The 



division of Scdecida comprising the Tape-worms, etc. 

 Plat-y-rhi'xa (Gr. _^>/a^«5, oroad ; rhi/ics, nostrils). A group of the Quadm- 



mana. 

 pLE-si-o-SAL''Rr9 (Gr. plesios, near to ; and sau-n/s, lizard). 

 Pleu'ea (Gr. for the side). The serous membrane covering the lung in tlie 



air-breathing Vertebrates. 

 Pleu'ron (Gr. pJeuron, a rib). The lateral extensions of the shell of Cmstacea. 

 Pli.:'te-us (Lat. for a pent-house). Tlie larval form of the Kddnoidt:a, 

 I'neu-Mj^-t'ic (Gr. pneuma, air). Filled with air. 

 pNEi'-iiAT'o-OYST (Gr. pneuma^ air; and kustis^ cyst). The air-sac or float of 



certain of the Oceanic Hydrozoa {^Phy?.op}ioHd(B). 

 Pkeu-mat'o-phore (Gr. pneurna^ air ; axi&phero, I carry). The proximal dilata- 

 tion of the cn.'nosarc in the P/i/jsophondcB which surrounds tlie pneumatocyst. 

 Pneu-mo-skel'e-ton ((4r. pimnna; and skeletos, 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 opnt/ialmos. eye). The division of 



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

 Pod-o-som'a-ta (Gr. pons, tV>ot ■ soma, body). An order oi Arachnid a. 

 Po-eph'a-ga {{}r. pjoc, grass; pnago, I cat;. A group of the Marsupials. 



PiJls'ERS. 



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

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



Pol-t-cys-ti'na (Gr. polus, manv ; and bustis, a c}'st}. An order of Protozoa, 

 with foraminated siliceous sliL-ll.s. 



Po-lyg'a-mous (Gr. polus ; and gartms, marriage). 



Pol-y-gas'tri-ca ((jr. />'"j///>i .' and ga-ster. stoniacli). The name applied by 

 Ehrenberg to the lufasoria, Lindcr the belief that they possessed many 

 stomachs. 



Pol'y-pa-ry (Gr. jpo/^^s/ and parlo, I produce). The hard chitinous cover- 

 ing secretea by many of tlie Hydrozoa. 



Void Yv^ {{jv. polus, m j.ny \ potis^f ooi). Restricted to the single individual 

 of a simple ActinozoiiTi, such as a Sea-anemune, or to the separate zouids of 

 a compound Actlnozorm. Often applied indiscrimiuately to any of the 

 Ccehntc}'ata. or even to the Polyzoa. 



PoL'Y-riDE, The separate zouid of a Polyzo'}n. 



PuL-Yp'i-noai. The dermal system of a colony of a Ilijdrozojn, or Polyzo''n. 



Pol'y-pite. The separate zooid of a Hydrozonn. 



Pol'y-stome (Gr. polm, many; ^nd stonia^vcionKh). Having many moutli= ; 

 applied to the Aclruite among the Protozoa. 



I'ol-y-tiial'a-m:ous (Gr. polus; and thalamos^ chamber). Having many 

 chambers ; appUed to the shells o'( Foramindjera and Cephalo/joda, 



Pol-y-zo'a (Gr. poltis; and -zo"n, animal). A division of the Molltiscoida. 

 comprising compouiid aiiimtUs, such as the Se;i-mat. Sometimes called 

 Sryozoa, 



