GLOSSARY. 



PSALTERIUM (Lat. a stringed instrument). The third stomach of Ruminants. 

 (See Omasum.) 



PSEUDEMBRYO (Gr. pseudos, false ; embruon, embryo). The larval form of an 

 Echinoderm. 



PSEUDOBRANCHIA (Gr. pseudos, false ; bragchia, gill). A supplementary gill 

 found in certain fishes, which receives arterialised blood only, and does 

 not, therefore, assist in respiration. 



PSEUDOH^IMAL (Gr. pseudos, false ; and haima, blood). Applied to the vas- 

 cular system of Annelida. 



PSEUDO-HEARTS. Certain contractile cavities connected with the atrial system 

 of Brachiopoda, and long considered to be hearts. 



PSKUDO-NAVICELL^E (Gr. pseiidos, false ; and Navicula, a genus of Diatoms). 

 The embryonic forms of the Gregarinidce, so called from their resemblance 

 in shape to the Navicula. 



PSEUDOPODIA (Gr. pseudos; and pous, foot). The extensions of the body- 

 substance which are put forth by the Rhizopoda at will, and which serve 

 for locomotion and prehension. 



PSEUDOVA (Gr. pseudos; Lat. ovum, egg). The egg-like bodies from which 

 the young of the viviparous Aphis are produced. 



PTEROPODA (Gr. pteron, wing ; and pous, foot). A class of the Mollusca which 

 swim by means of fins attached near the head. 



PTEROSAURIA (Gr. pteron, wing; saura, lizard). An extinct order of Reptiles. 



PUBIS (Lat. pubes, hair). The share-bone ; one of the bones which enter into 

 the composition of the pelvic arch of Vertebrates. 



PULMONARIA. A division of Arachnida which breathe by means of pulmo- 

 nary sacs. 



PULMONATE. Possessing lungs. 



PULMONIFERA (Lat. puhno, a lung; and fero, I carry). The division of 

 Mollusca which breathe by means of a pulmonary chamber. 



PULMOGASTEROPODA (= Pulmonifera). 



PUPA (Lat. a doll). The stage of an insect immediately preceding its appear- 

 ance in a perfect condition. In the pupa-stage it is usually quiescent when 

 it is often called a " chrysalis " but it is sometimes active when it is often 

 called a " nymph." 



PYLORUS (Gr. puloros, a gate-keeper). The valvular aperture between the 

 stomach and the intestine. 



PYRIFORM (Lat. pyrus, a pear ; and forma, form). Pear-shaped. 



QUADRUMANA (Lat. quatuor, four; manus, hand). The order of Mammals 

 comprising the Apes, Monkeys, Baboons, Lemurs, &c. 



RADIATA (Lat. ^radius, a ray). Formerly applied to a large number of animals 



which are now placed in separate sub-kingdoms (e.g., the Ccelenterata, the 



Bchvnodermata, the Infusoria, &c. ) 



RADIOLARIA (Lat. radius, a ray). A division of Protozoa. 

 RADIUS (Lat. a spoke or ray). The innermost of the two bones of the fore- 

 arm of the higher Vertebrates. It carries the thumb, when present, and 



corresponds with the tibia of the hind-limb. 

 RAMUS (Lat. a branch). Applied to each half or branch of the lower jaw or 



mandible of Vertebrates. 



RAPTORES (Lat. rapto, I plunder). The order of the Birds of Prey. 

 RASORES (Lat. rado, I scratch). The order of the Scratching Birds (Fowls, 



Pigeons, &c.) 

 RATIT.E (Lat. rates, a raft). Applied by Huxley to the Cursorial Birds which 



do not fly, and have, therefore, a raft-like sternum without any median 



keel. 

 RECTUM (Lat. rectus, straight). The terminal portion of the intestinal canal, 



opening at the surface of the body at the anns. 

 REPTILIA (Lat. repto, I crawl). , The class of the Vertebrata comprising the 



Tortoises, Snakes, Lizards, Crocodiles, &c. 

 RETICULARIA (Lat. reticulum, a net). Employed by Dr Carpenter to desig- 



