GLOSSARY. 3s;) 



Per-en-ni-bran-chi-a'ta (Lat. v^rennis^ perpetual; Gr. hragcliia^ gills"). Ap- 

 plied to those Aiiijpldhia in w£.ich the gills are permanently retained tiiroiigli- 

 out life. 



pER-GA-iiEN-TA'cEous (Lat. pergameua^ parchment). Of the texture of parch- 

 ment. 



FER-i-CAit'Di-iTur (Qy. peH^ around; hardla^ heart). The serous membrane in 

 which the heart is contained. 



Per'i-derm (G-r. peH^ around ; and derma, skin). The hard cuticular layer 

 which is developed by the coenosarc of certain of the Hydrozoa. 



Per-i-gas'tric (Gr./>eW, around ; and^a.'^^;', stomach). The peri.itastric space 

 IS the cavity which surrounds the stomach and other viscera, corr.'..sponding 

 to the abdominal cavity of the higher animals. 



Per-i-os'tea-cum (Gr. iK-i'i : and ostrakoii shell). The layer of epidermis 

 which covers the shell in most of the Mollusca. 



Per'i-plast (Gr. /56/'// and piasso^ Tmould). The intercellular substance or 

 matrix in wliich the oro-anized structures of a tissue are embedded. 



Per'i-some {Qr.peri ; andso;?2.a, body). The coriaceous or calcareous integu- 

 ment of the Echinodermata. 



Per-is-so-dac'ty-la {Gy. perissos, uneven ; dahtulos^ finger). Applied to those 

 Hoofed Quadrupeds {Jfngulata) in whicii the feet have an uneven number 

 of toes. 



Per'i-stome fGr. peri ; and stovia^ mouth). The space which intervenes be- 

 tween the moutli and the margin of the calyx in Vortlcella ; also the space 

 between the mouth and the tentacles in a sea-anemone {Actinia) \ also the 

 lip or margin of the mouth of a univalve shell. 



Per-i-vis'ce-ral (Gr. peri ; and Lat. viscera^ the internal organs). Applied 

 to the space surrounding the viscera. 



Pet'a-loid. Shaped like the petal of a flower. 



Pha-lan'ges {GrY. plialagx,^ a row). The small bones composing the digits of 

 the higher Vertthrata. Normally each digit has three phalanges. 



Phar-yn-go-eran'chi-i (Gr. pharugx, pharynx; hragchia^ giUs). The order 

 of Fishes comprising only the Lancelet. 



Phar'tnx. The dilated commencement of the gullet. 



Phrag'ma-cone (Gr. p\rag'r}ia^ a partition ; and honos^ a cone). The chaui- 

 bered portion of the internal shell of a Belemniti'. 



Pht-lac-to-l^m:'a-ta (Gr. pkulasso, I guard ; and laimos, throat). The divi- 

 sion of Polyzoa in which the mouth is provided with the arched valvular 

 process known as the " epistome." 



Phtl'lo-ctsts {(jy. phullon-^ leaf; ixndilcustis^ a cyst). The cavities in the in- 

 terior of the '• hydroph>'llia " of certain of the Oceanic Ilydrozoa. 



Phyl-lop'o-da (Gy. p?iullon, leaf; and pous^ foot). An order of Crustacea. 



Phy-o-gem-ma'ri-a (Gr. p?iuo, I produce ; and Lat. gemma, budj. The small 

 gonoblastidia of Felelta, one of the Pkymp}tori<lad. 



I*ht-so-gra'da (Gr. phusa^ bellows or air-bladder ; and Lat. gradior, 1 walk). 

 Applied formerly to the Physopliorldce.^ aa order of Oceanic Hydrozoa^ ia 

 which a " float " is present. 



Pht-so-phor'i-d.e {Gy. pkusa, air-bladder; ix\\<\ phero^ I carry). An order of 

 Oceanic Hydrozoa. 



Phy'toid (Gr. phnton, a plant ; and eidos, form i. Plant-like, 



Pi-iY-TOPn'A-aofs (Gr. pliuto/i, a plant; and pkago^ 1 eatj. Plant-eating, oi 

 herbivorous. 



Pin'n^. 



Pin'nate (Lat. piiina^ a feather). Feather-shaped, or possessing lateral pro- 

 cesses. 



Pin-ni-gea'da (LdX. pi)ina^ a feather; gradior^ 1 walk). The ^roup of Cat- 

 nivora, comprising the Seals and Walruses, adapted for aquatio life. Often 

 called Plnnipedia. 



Pin'nu-l^ (Lat. dim. of_^n?i«a.) The lateral processes of the arms of C'ri- 

 noids. 



Pis'oEs (Lat. piscis, a flsh). The class of Vertebrates comprising the Fishes. 



Pla-cen'ta (Lat. for a caks.) The '^ after-birth," or the organ by wliich a 



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