504 GLOSSAEY. 



TraLOBiTA (Gr. treis, three ; lobos, a lobe). An extinct order of Crustaceans. 



Trochanter (Gr. trecho, I turn). A process of the upper part of the thigh- 

 bone (femur) to which are attached the muscles which rotate the limb. 

 There may be two, or even three, trochantei-s present. 



Trochoid (Gr. trochos, a wheel ; and eidos, form). Conical with a flat base ; 

 applied to the shells of Foraminifcra and Univalve Molluscs. 



Trophi (Gr. tro2}hos, a nourisher). The parts of the mouth in insects which 

 are concerned in the acquisition and preparation of food. Often called 

 "instrumeuta cibaria." 



Trophosome (Gr. U-epho, I nourish ; and so7na, body). Applied collectively 

 to the assemblage of the nutritive zooids of any Hydrozoon. 



Truncated (Lat. trunco, I shorten). Abruptly cut off ; applied to univalve 

 shells, the apex of whicli breaks off, so that the shell becomes ' ' decol- 

 lated." 



TuBicoLA (Lat. tuba, a tube; and colo, I inhabit). The order of Annelida 

 which constinct a tubular case in which they protect themselves. 



TuBicOLOUS. Inhabiting a tube. 



TuNiCATA (Lat. tunica, a cloak). A class oi Mollmcoida which are enveloped 

 in a tough leathery case or "test." 



Turbinated (Lat. turbo, a top). Top-shaped ; conical with a round base. 



Ulna (Gr. olene, the elbow). The outermost of the two bones of the fore-arm, 



corresponding with the fibula of the hind-limb. 

 Umbellate (Lat. umhclla, a parasol). Forming an umbel — i.e., a number of 



nearly equal radii all proceeding from one point. 

 Umbilicus (Lat. for navel). The aperture seen at the base of the axis of 



certain univalve shells, which are then said to be "perforated" or " um- 



bilicated." 

 Umbo (Lat. the boss of a shield). The beak of a bivalve shell. 

 Umbrella. The contractile disc of one of the Lucernarida. 

 Uncinate (Lat. uncinus, a hook). Provided with hooks or bent sj)ines. 

 Unguiculate (Lat. unguis, nail). Furnished with claws. 

 Ungulata (Lat. tmgula, hoof). The order of Mammals comprising the 



Hoofed Quadrupeds. 

 Ungulate. Furnished with expanded nails constituting hoofs. 

 Unilocular (Lat. unios, one ; and loculus, a little purse). Possessing a single 



cavity or chamber. Applied to the shells of Foraminifera and Mollusca. 

 Univalve (Lat. unus, one ; valvce, folding-doors). A shell composed of a 



single piece or valve. 

 Urodela (Gr. oura, tail; delos, visible). The order of the Tailed Amphi- 

 bians (Newts, &c.) 



Varices (Lat. varix, a dilated vein). The ridges or spinose lines which mark 



the former position of the mouth in certain univalve shells. 

 Vascular (Lat. vas, a vessel). Connected with the circulatory system. 

 Ventral (Lat. venter, the stomach). Ptclating to the inferior surface of the 



body. 

 Vermes (Lat. vermis, a worm). Sometimes emploj'ed at the present day in 



the same, or very nearly the same, sense as Annuloida, or as Annuloida 



plus the Anarthropoda. 



