502 GLOSSARY, 



SiKENiA (Gr. sciren, a mermaid). The order of Mammalia comprising the 

 Dugongs and Manatees. 



SoLiDUNGULA (Lat. solidus, solid ; ungula, a hoof). The group of Hoofed 

 Quadrupeds comprising the Horse, Ass, and Zebra, in whicli each foot has 

 only a single solid hoof. Often called SoUjxdia. 



Somatic (Gr. soma, body). Connected with the body. 



Somite (Gr. soma). A single segment in the body of an Articulate animal. 



Spermatozoa (Gr. spei'ma, seed ; and zod7i, animal). The microscopic fila- 

 ments which form the essential generative element of the male. 



Spicula (Lat. sjnculum, a point). Pointed needle-shaped bodies. 



Spiracles (Lat. sjnro, I breathe). The breathing-pores, or apertures of the 

 breathing-tubes (tracheae) of Insects. Also the single nostril of the Hag- 

 fishes, the "blow-hole" of Cetaceans, &c. 



Splanchnoskeleton (Gr. splagchna, viscera ; skeletos, dry). The hard struc- 

 tures occasionally developed in connection with the internal organs or 

 viscera. 



Sponge- particles — see Sarcoids. 



Spongida (Gr. si)oggos, a sponge). The division of Protozoa commonly known 

 as Sponges. 



Squamata (Lat. squama, a scale). The division of Reptiles comprising the 

 OpMdia and Lacertilia, in which the integument develops horny scales, but 

 there are no dermal ossifications. 



Stellerida (Lat. stella, star). Sometimes employed to designate the order of 

 the Star-fishes. 



Stelliform. Star-shaped. 



Sternum (Gr. sternon). The breast-bone. 



Stolon (Gr. stolos, a sending forth). Off'shoots. The connecting processes 

 of sarcode, iw Foraminifera ; the connecting tube in the socisl Ascidians ; 

 the processes sent out by the ccenosarc of certain Actinozoa. 



Stomapoda (Gr. stoma, mouth ; j'ous, foot). An order of Crustcccea. 



Stomatode (Gr. stoma). Possessing a mouth. The Infusoria are thus often 

 called the Stomatode Protozoa. 



Strepsiptera (Gr. strcplio, I twist ; and pteron, wing). An order of Insects 

 in which the anterior wings are represented by twisted rudiments. 



Strepsirhina (Gr. strcpho, I twist ; rhincs, nostrils). A group of the Qiiad- 

 rumana, often spoken of as Prosimioi. 



Styliform (Lat. stylus, a pointed instrument ; forma, form). Pointed in 

 shape. 



Sub-calcareous. Somewhat calcareous. 



Sub-central. Nearly central, but not quite. 



Sub-pedunculate. Supported upon a very short stem. 



Sub-sessile. Nearly sessile, or without a stalk. 



Suture (Lat. suo, I sew). The line of junction of two parts which are 

 immovably connected together. Applied to the line where the whorls 

 of a univalve shell join one another ; also to the lines made upon the 

 exterior of the shell of a chambered Ccplialopod by the margins of the 

 septa. 



SwiMMERETS. The limbs of Crustacea, which are adapted for swimming. 



Symphysis (Gr. sicmphusis, a growing together). Union of two bones in 

 which there is no motion or but a very limited amount. 



