GLOSSARY. 597 



nate those Protozoa, such as the Foraminifera, in which the pseudopodia 

 run into one another and form a network. 



RETICULUM (Lat. a net). The second division of the complex stomach of 

 Ruminants, often called the "honeycomb bag." 



REVERSED. Applied to spiral univalves, in which the direction of the spiral 

 is the reverse of the normal i.e., sinistral. 



RHIZOPHAGA (Gr. rhiza, root ; phago, I eat). A group of the Marsupials. 



RHIZOPODA ((Jr. rhiza, a root ; and pous, foot). The division of Protozoa com- 

 prising all those which are capable of emitting pseudopodia. 



RHYNCHOLITES (Gr. rhunckos, beak ; and lithos, stone). Beak-shaped fossils, 

 consisting of the mandibles of Cephalopoda. 



RODENTIA (Lat. rodo, I gnaw). An order of the Mammals ; often called Glires 

 (Lat. gli-s, a dormouse). 



ROSTRUM (Lat. rostrum, beak). The "beak" or suctorial organ formed by 

 the appendages of the mouth in certain insects. 



ROTATORIA (= Rotifera). 



ROTIFERA. (Lat. rota, wheel ; and fe.ro t I carry). A class of the Scolecida 

 (Annuloida) characterised by a ciliated "trochal disc." 



RUGOSA (Lat. rugosus, wrinkled). An extinct order of Corals. 



RUMEN (Lat. the throat). The first cavity of the complex stomach of Rumi- 

 nants; often called the "paunch." 



RUMINANTIA (Lat. ruminor, I chew the cud). The group of Hoofed Quadru- 

 peds (Ungulata) which " ruminate" or chew the cud. 



SACRUM. The vertebrae (usually anchylosed) which unite with the haunch- 



bonqs (ilia) to form the pelvis. 

 SAND-CANAL (= STONE-CANAL). The tube by which water is conveyed from 



the exterior to the ambulacral system of the Echinodermata. 

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



bodies of Protozoa are composed. It is an albuminous body containing oil- 

 granules, and is sometimes called "animal protoplasm." 

 SARCOIDS (Gr. sarx; and eidos, form). The separate amoebiform particles 



which in the aggregate make up the " flesh" of a Sponge. 

 SAURIA (Gr. saura, a lizard). Any lizard-like Reptile is often spoken of as a 



"Saurian;" but the term is sometimes restricted to the Crocodiles alone, 



or to the Crocodiles and Lacertilians. 

 SAUROBATRACHIA (Gr. saura; batracJios, frog). Sometimes applied to the 



order of the tailed Amphibians (Urodela). 

 SAUROPSIDA (Gr. saura; and opsis, appearance). The name given by Huxley 



to the two classes of the Birds and Reptiles collectively. 

 SAUROPTERYGIA (Gr. saura; pterux, wing). An extinct order of Reptiles, 



called by Huxley Plesiosauria, from the typical genus Plesiosaurus. 

 SAURURJE (Gr. saura; oura, tail). The extinct order of Birds comprising 



only the Archceopteryx, 

 SCANSORES (Lat. scand'o, I climb). The order of the Climbing Birds (Parrots, 



Woodpeckers, &c. ) 

 SCAPHOGNATHITE (Gr. skaphos, boat; and gnatlios, jaw). The boat-shaped 



appendage (epipodite) of the second pair of maxillae in the Lobster ; the 



function of which is to spoon out the water from the branchial chamber. 

 SCAPULA (Lat. for shoulder-blade). The shoulder-blade of the pectoral arch 



of Vertebrates ; in a restricted sense, the row of plates in the cup of 



Crinoids, which give origin to the arms, and are usually called the "axillary 



radials." 

 SCLERENCHYMA (Gr. sMeros, hard ; and enchuma, tissue). The calcareous 



tissue of which a coral is composed. 

 SCLERITES (Gr. skleros}. The calcareous spicules which are scattered in the 



soft tissues of certain A ctinozoa. 

 SCLEROBASIC (Gr. skleros, hard ; basis, pedestal). The coral which is produced 



by the outer surface of the integument in certain Actinozoa (e.g., Red Coral), 



and forms a solid axis which is invested by the soft parts of the animal. It 



is called " foot- secretion" by Mr Dana. 



