GLOSSARY. 373 



Parietal (Lat. paries, a wall). Connected with the walls of a cavity or o£ 



the body. 

 PARiETO-sptANOHMC {Ij&l. paHes, a wall; Gr. sp^apcAnom, an internal organ). 



Applied to one of the nervouis ganglia of the Mollusca, which supplies the 



walls of the body and the viscera. 

 Pataoium (Lat. the border of a dress). Applied to the expansion of the 



integument by which Bats, Flying Squirrels, and other animals support 



themselves in the air. 

 Pectoral (Lat. pectus, the breast). Connected with the chest. 

 Pedal (Lat. pes, the foot). Connected with the foot ; generally used in con- 

 nection with the MoUiisca. 

 Pedicellari^ (Lat. pedicellws, a louse). Curious appendages found in many 



Echinodenns, attached to the surface of the body, and resembling a little 



pair of pincers supported on a stalk. 

 Pbdipalpi (Lat. pes, foot; palpo, I feel). An order of Arachnida comprising 



the Scorpions, &c. 

 Pedunculated (Lat. pedunculus, a stem). Supported -upon a stem or stalk. 

 Pelvis (Lat. basin). The bony arch with which the lower or posterior pair of 



limbs is connected in many Vertebraia. 

 PBRENNiBRANcniATA (Lat. perennis, perpetual ; Gr. bragchia, gills). Applied 



to those Amphibia which retain their gills throughout life. 

 Perissodactyla (Gr. perissos, uneven ; daktulos, finger). Applied to those 



Hoofed Mammals ( Ungulata) which' have an uneven number of toes. 

 Perivisceral (Gr. peri, around ; Lat. viscera, the internal organs). Applied 



to the space surrounding the viscera in most animals. 

 Phalanges (Gr. phalanx, a row). The small bones composing the digits of 



the higher Vertebrates. Normally each digit has three phalanges. 

 Pharyngobranchii (Gr. pharugt, the pharynx ; bragchia, gills). The order 



of Fishes comprising only the Lancelet. 

 Pharynx. The upper part of the gullet. 



Phyllopoda (Gr. phullcn, leaf ; podes, feet). An order of Crustacea. 

 Physophorid^ (Gr. phusa, bellows or air-bladder ; phero, I carry). An order 



of Oceanic Hydrozoa. 

 PlNN^ (Lat. pinna, a feather). Lateral processes, applied especially to the 



processes of the arms of Crinoids, or of the tentacles of A Icyonaria. 

 PiNNIQRADA (Lat. pinna ; and gradior, I walk). The family of Carnivora, 



comprising the Seals and Walruses, adapted for an aquatic life. 

 Pisces (Lat. piscis, a fish). The claiss of the Vertebrata comprising the 



Fishes. 

 Placenta (Lat. a cake). The " after-birth," or the organ by which a vascular 



connection is establi.shed in the higher Vertebrata between the mother and 



the young animal previous to its birth. 

 Placental. Possessing a placenta, or connected with the placenta. 

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



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

 Plagiostomi (Gr. ptagios, transverse ; stoma, mouth). The Sharks and Rays, 



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



head. 

 Planarida (Gr. plane, wandering). A group of the Scolecida. 

 Plantighada (Lat. planta, the sole of the foot ; gradior, I walk). The 



group of the Carnivora in which the sole of the foot is applied to the 



ground. 

 Plahtigradb. Walking upon the soles of the feet. 

 Plastron (Gr. emplastron, a plaster). The ventral shield of the case of the 



Tortoises and Turtles (Ghelonia). 

 Platyrhina (Gr. plains, broad ; rhines, nostrils). A group of the (^wxdru- 



mana. 

 Plesiosauria (Gr. plesios, near; saura, a lizard). An extinct order of 



Reptiles. 

 Pluteus (Lat. a shed). The larval form of the Sea-urchins (Echinus). 

 Pneumatic (Gr. pneuma, air). Filled with air. 



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