GLOSSARY. 393 



SESSILE (Lat. sedo, I sit). Not supported upon a stalk or peduncle; attached 



by a base. 



SETJE (Lat. bristles). Bristles or long stiff hairs. 

 SIGILLARIOIDS (Lat. sigilla, little images). A group of extinct plants of which 



Sigillaria is the type, so called from the seal-like markings on the bark. 

 SILICEOUS (Lat. silex, flint). Composed of flint. 



SINISTRAL (Lat. sinistra, the left hand). Left-handed ; applied to the direc- 

 tion of the spiral in certain shells, which are said to be " reversed." 

 SIPHON (Gr. a tube). Applied to the respiratory tubes in the Mollusca ; 



also to other tubes of different functions. 

 SIPHONIA (Gr. siphon, a tube). A genus of fossil Sponges. 

 SIPHONOSTOMATA (Gr. siphon ; and stoma, mouth). The division of Gastero- 



podous Molluscs in which the aperture of the shell is not " entire," but 



possesses a notch or tube for the emission of the respiratory siphon. 

 SIPHUNCLE (Lat. siphunculus, a little tube). The tube which connects to- 

 gether the various chambers of the shell of certain Cephalopoda (e.g., the 



Pearly Nautilus). 

 SIRENIA (Gr. seiren, a mermaid). The order of Mammalia comprising the 



Dugongs and Manatees. 

 SIVATHERIUM (Siva, a Hindoo deity ; Gr. therion, beast). An extinct genus 



of Hoofed Quadrupeds. 

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



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



only a single solid hoof. Often called Solipedia. 

 SPHENOPTERIS (Gr. sphen, a wedge ; pteris, a fern). An extinct genus of 



ferns. 



SPICULA (Lat. spiculum, a point). Pointed needle-shaped bodies. 

 SPIRIFERA (Lat. spira, a spire or coil ; fero, I carry). An extinct genus of 



Brachiopods, with large spiral supports for the "arms." 

 SPIRORBIS (Lat. spira, a spire ; orbis, a circle). A genus of tube-inhabiting 



Annelides, in which the shelly tube is coiled into a spiral disc. 

 SPONGIDA (Gr. spoggos, a sponge). The division of Protozoa commonly known 



as sponges. 

 STALACTITES (Gr. stalasso, I drop). Icicle-like encrustations and deposits of 



lime, which hang from the roof of caverns in limestone. 

 STALAGMITE (Gr. stalagma, a drop). Encrustations of lime formed on the floor 



of caverns which are hollowed out of limestone. 

 STIGMARIA (Gr. stigma, a mark made with a pointed instrument). A genus 



founded on the roots of various species of Sigillaria. 

 STRATUM (Lat. stratus, spread out ; or stratum, a thing spread out). A layer 



of rock. 

 STROMATOPORA (Gr. stroma, a thing spread out ; poros, a passage or pore). A 



Palaeozoic genus of Protozoa. 

 STROPHOMENA (Gr. strophao, I twist ; men$, moon). An extinct genus of 



Brachiopods. 



SUB-CALCAREOUS. Somewhat calcareous. 

 SUB-CENTRAL. Nearly central, but not quite. 



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

 ably 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 Cephalopod by the margins of the septa. 

 SYRINGOPORA (Gr. surigx, a pipe ; poros, a pore). A genus of Tabulate Corals. 



TABULAE (Lat. tabula, a tablet). Horizontal plates or floors found in some 

 Corals, extending across the cavity of the " theca " from side to side. 



TEGUMENTARY (Lat. tegumentum, a covering). Connected with the integu- 

 ment or skin. 



TELEOSAURUS ^Gr. teleios, perfect ; saura, lizard). An extinct genus of Cro- 

 codilian Reptiles. 



TFLKOSTEI (Gr. teleios, perfect; osteon, bone). Ths order of the "Bony 

 Fishes." 



