GLOSSARY. 343 



PER-EN-NI-BRAN-CHI-A'TA (Lat. perennis, perpetual ; Gr. bragchia, gills). Ap- 

 plied to those Amphibia in which the gills are permanently retained through- 

 out life. 



PER-GA-MEN-TA'CEOTJS (Lat. pergamena, parchment). Of the texture of parch- 

 ment. 



PER-I-CAR'DI-TTM (Gr. peri, around ; Icardia, heart). The serous membrane in 

 which the heart is contained. 



PER'I-DERM (Gr. peri, around ; and derma, skin). The hard cuticular layer 

 which is developed by the crenosarc of certain of the Uydrozoa. 



PER-I-GAS'TRIC (Gr. peri, around : and gaster, stomach). The perigastric space 

 is the cavity which surrounds the stomach and other viscera, corresponding 

 to the abdominal cavity of the higher animals. 



PER-I-OS'TRA-CUM (Gr. peri; and ostrakon, shell). The layer of epidermis 

 which covers the shell in most of the Mollusca. 



PER'I-PLAST (Gr. peri; and p^lasso, I mould). The intercellular substance or 

 matrix in which the organized structures of a tissue are embedded. 



PER'I-SOME (Gr.peri ; ancUoma, body). The coriaceous or calcareous integu- 

 ment of the Echinodermata. 



PER-IS-SO-DAC'TY-LA (Gr.perissos, uneven ; daktulos, finger). Applied to those 

 Hoofed Quadrupeds ( Ungulata) in which the feet have an uneven number 

 of toes. 



PER'I-STOME (Gr. peri; and stoma, mouth). The space which intervenes be- 

 tween the mouth and the margin of the calyx in Vorticdla ; 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 (Gr. phalagx, a row). The small bones composing the digits of 

 the higher Vertebrata. Normally each digit has three phalanges. 



PIIAR-YN-GO-BRAN'CHI-I (Gr. vharugx, pharynx ; bragch^a, gills). The order 

 of Fishes comprising only the Lancelet. 



PHAR'YNX. The dilated commencement of the gullet. 



PHRAG'MA-CONE (Gr. phragma, a partition and konos, a cone). The cham- 

 bered portion of the internal shell of a Belemnite. 



PH Y-LAC-To-L.fi M'A-T- A (Gr. phulasso, I guard ; and laimos, throat). The divi- 

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

 yjrocess known as the " epistome." 



PHYL'LO-CYSTS (Gr. phullon, leaf; undkustis, a cyst). The cavities in the in- 

 terior of the " hydrophyllia " of certain of the Oceanic Hydrozoa. 



PHYL-LOP'O-DA (Gr. phullon, leaf ; and pous, foot). An order of Crustacea. 



PHY-O-GEM-MA'RI-A ( (Jr. pkuo, I produce ; and Lat. gemma, bud). The small 

 gonoblastidia of Velella, one of the Physophwidce. 



PHY-SO-GRA'DA (Gr. phusa, bellows or air-bladder ; and Lat. gradior, I walk). 

 Applied formerly to the Physophoridoe, an order of Oceanic Hydrozoa, in 

 which a " float " is present. 



PHY-SO-PHOR'I-D^: (Gr. phusa, air-bladder ; audphero, I carry). An order of 

 Oceanic Hydrozoa. 



PHY'TOID (Gr. pJiuton, a plant ; and eidos, form). Plant-like. 



PHY-TOPH'A-SOUS (Gr. ptiuton, a plant ; and phago^ I eat). Plant-eating, or 

 herbivorous. 



PIN'N^E. 



PIN'NATE (Lat. pinna, a feather). Feather-shaped, or possessing lateral pro- 

 cesses. 



PIN-NI-GRA'DA (Lat. pinna, a feather: qradior, I walk). The group of Car- 

 nivora, comprising the Seals and Walruses, adapted for aquatic lire. Often 

 called Pinmpedia. 



PIN'NC-LJS (Lat. dim. of pinna.) The lateral processes of the arms of Ori- 

 noids. 



PIS'CES (Lat. piscis, a fish). The class of Vertebrates comprising the Fishes. 



PIA-CEN'TA (Lat. for a cake.) The " after-birth," or the organ by which a 



