170 ZOOLOGY. 



Pseudo-haemal (Gr. pseudos, false; liaima, blood) Applied to the 

 circulatory system of the Annelida. 



Pseudo-hearts Contractile cavities found in the Brachiopoda, 

 formerly believed to be hearts. 



Pseudo-Navicellse (Gr. pseudos; Navicula, a diatom) The unde- 

 veloped form of the Gregarinida. 



Pseudo-podia (Gr. pseudos; pous, foot) Processes thrust out by 

 the Rhizopoda from the surface of their bodies, which serve 

 the purpose of limbs. 



Pteropoda (Gr. pteron, wing ; pous, foot) A class of Mollusca which 

 swim by means of wing-like processes attached to the head. 



Pulmo-Gasteropoda A group of Gasteropods which breathe by 

 pulmonary sacs or lungs. 



Pupa (Lat. a doll) The stage of metamorphosis of an insect in- 

 termediate between the larva and imago. It is also called a 

 chrysalis. 



Radiata (Lat. radius, a ray) One of the sub-kingdoms of Cuvier. 

 This group is now broken up, its members being assigned 

 to several sub-kingdoms (Ccelenterata, Annuloida, Proto- 

 zoa,, &c.) 



Radiolaria (Lat. radius, a ray) A class of Protozoa, including tho 



Polycystina. 



\ Radius One of the two bones of the fore-arm of the higher 

 vertebrates. 



Ramus (Lat. a branch) One of the halves of the lower jaw in 

 the Vertebrata. 



Reptilia (Lat. repo, I creep) A class of Vertebrata, including 

 crocodiles, lizards, serpents, and tortoises. 



Rhizopoda (Gr. rhiza, root; pous, a foot) A class of Protozoa 

 which have the power of pushing out pseudopodia. These 

 processes have the appearance of roots. 



Rotifera (Lat. rota, wheel ; fero, I carry) A group of microscopic 

 animals belonging to the class Scolecida. The mouth is sur- 

 rounded by fringes of cilia, which, when in motion, resemble 

 a pair of toothed wheels. 



Rugosa (Lat. ruyosus, wrinkled) An extinct group of corals. 



v Sacrum The vertebrae which articulate with the haunch bones 

 to form the pelvis. 



Sarcode (Gr. sarx, flesh; eidos, form) The jelly-like substance of 

 which the bodies of the Protozoa are formed. It is some- 

 times called protoplasm. 



Scapula The shoulder blade. 



Sclerobasic (Gr. sderos, hard; basis, the foundation) A term 

 applied to the red coral, because it is secreted by the united 

 bases of the polypes. 



