394 GLOSSARY. 
TELSON (Gr. a limit). The last joint in the abdomen of Crustacea; va- 
riously regarded as a segment without appendages, or as an azygous 
appendage. 
TENTACULITES (Lat. tentaculum, a feeler). A genus of Pteropoda, 
‘TEREBRATULA (Lat. terebratus, bored or pierced). A genus ot Brachiopoda, so 
called in allusion to the perforated beak of the ventral valve. 
Test (Lat. testa, shell). The shell of Mollusca, which are for this reason 
sometimes called ‘‘ Testacea ;” also, the calcareous case of Echinoderms ; 
also, the thick leathery outer tunic in the 7unicata. 
TEsTACEOUS, Provided with a shell or lard covering. 
TESTUDINID& (Lat. testudo, a tortoise). The family of the Tortoises. 
TETRABRANCHIATA (Gr. tetra, four ; bragchia, gill). The order of Cephalopoda 
characterised by the possession of four gills. 
TEXTULARIA (Lat. textilis, woven). <A genus of Foraminifera. 
THECA (Gr. théké, asheath). A genus of Pteropods. 
THECODONTOSAURUS (Gr. théké, a sheath; odous, tooth; saura, lizard). A 
genus of ‘‘Thecodont ” Reptiles, so named in allusion to the fact that the 
teeth are sunk in distinct sockets. 
THERIODONT (Gr. thérion, a beast ; odous, tooth). A group of Reptiles so 
named by Owen in allusion to the Mammalian character of their teeth. 
THORAX (Gr. a breastplate). The region of the chest. 
THYLACOLEO (Gr. thulakos, a pouch ; leo, alion). An extinct genus of Mar- 
supials, 
TRIGONIA (Gr. treis, three ; gonia, angle). A genus of Bivalve Molluscs. 
TRIGONOCARPON (Gr. treis, three; gonia. angle; karpos, fruit). A genus 
founded on fossil fruits of a three-angled form. 
TRILOBITA (Gr. ¢reis, three ; lobos,a lobe). An extinct order of Crustaceans. 
TRINUCLEUS (Lat. tris, three ; nucleus, a kernel). A genus of Trilobites. 
TROGONTHERIUM (Gr. trogo, I gnaw; thérion, beast). An extinct genus of 
Beavers. 
TuBICOLA (Lat. tuba, a tube; and colo, I inhabit). The order of Annelida 
which construct a tubular case in which they protect themselves. 
TUBICOLOUS. Inhabiting a tube. 
Tuntcata (Lat. tunica, a cloak). A class of Molluscoida which are enveloped 
in a tough leathery case or ‘‘ test.” 
TURBINATED (Lat. turbo, atop). Top-shaped ; conical with a round base. 
TURRILITES (Lat, turris, a tower). A genus of the Amimonitide. 
Umso (Lat. the boss of a shield), The beak of a bivalve shell. 
UNGUICULATE (Lat. unguis, nail). Furnished with claws. 
Uncuxata (Lat. wngula, hoof). The order of Mammals comprising the Hoofed 
Quadrupeds. 
UneuLate. Furnished with expanded nails constituting hoofs. 
UNILocuULaR (Lat. wnus, one; and loculus. a little purse). Possessing a single 
€avity or chamber. Applied to the shells of Foraminifera and Mollusca. 
UNIVALVE (Lat. unus, one; valve, folding-doors). A shell composed of a 
single piece or valve. 
URODELA (Gr. oura, tail ; delos, visible). The order of the Tailed Amphibians 
(Newts, Xc.) 
prea (Lat. venter, the stomach). Relating to the inferior surface of the 
ody. 
pe (Lat. ventriculum, a little stomach). A genus of siliceous 
_ Sponges. 
VERMIFORM (Lat. vermis, worm ; and forma, form). Worm-like. 
VERTEBRA (Lat. verto, I turn). One of the bony segments of the vertebral 
_column or backbone. 
\ ERTEBRATA (Lat. vertebra, a bone of the back, from vertere, to turn). The 
division of the Animal Kingdom roughly characterised by the possession of 
_a backbone, 
VESICLE (Lat. vesica, a bladder). A little sac or cyst. 
