GLOSSARY, 393 
SESSILE (Lat. sedo, I sit), Not supported upon a stalk or peduncle; attached 
by a base. 
oes (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. silexz, flint). Composed of flint. 
SINISTRAL (Lat. s¢nistra, 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, atube). 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.y., the 
Pearly Nautilus). 
SIRENIA (Gr. seiren, a mermaid). The order of Mammalia comprising the 
Dugongs and Manatees. 
SIVATHERIUM (Siva, a Hindoo deity ; Gr. thérion, 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. sphén, 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. spiva, 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, asponge). 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 stratwm, athing spread out). A layer 
of rock. 
STROMATOPORA (Gr. stroma, a thing spread out ; poros, a passage or pore). A 
Paleozoic genus of Protozoa. 
STROPHOMENA (Gr. strophao, I twist; méné, moon). An extinct genus of 
Brachiopods. . 
SUB-CALCAREOUS. Somewhat calcareous. 
SUB-CENTRAL. Nearly central, but not quite. 
SUTURE (Lat. swo, 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. surigz, a pipe ; poros,a pore). A genus of Tabulate Corals. 
TABULE (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. ¢eleios, perfect ; sawra, lizard). An extinct genus of Cro- 
codilian Reptiles. 
TELEOSTEL (Gr. ¢eleios, perfect; osteon, bone). The order of the ‘Bony 
Fishes.” 
