402 INDEX- GLOSSARY. 



Tubules Uriniferous, 167, 205, 250, 295. 



Tympanic area, 175. 



Tympanic cavity, 189. 



Tympanum (TU/JLTTUVOV, tympanum, a drum) The cavity of the middle ear, 



219, 255, 304. 

 Typhlosole (rw0A.flf, blind ; O-AXV, a channel, a fold), in some Invertebrates 



A longitudinal fold of the intestinal wall which projects inwards, 57, 



133, 313. 



U 



Umbilical cord, 310. 



Umbilicus, 231. 



Umbo (umbo, the boss in the centre of a shield) A projection constituted 



by the oldest part of the shell, 109. 



Uncinus (oyKtvos), uncinus, a small hook), in the Snail One of the symme- 

 trical median teeth of the radula, 126. 

 Ungulata, 346, 354. 

 Unicellular, 20, 310. 



Unio (Fresh-water Mussel), 109-122, 341. 

 Unipolar, 145. 

 United States, 349. 

 Univalve, 123. 

 Urea, 118, 206, 297. 



Ureter The kidney-duct, 98, 118, 129, 166, 250, 265, 295, 333, 334. 

 Urethra The urinogenital canal of the male Rabbit, 298. 

 Uric acid, 99, 118, 251. 

 Urine, 62, 251. 

 Urinogenital system Rana, 205 ; Scyllium, 166 ; Columba, 250 ; Lepus, 



293 ; Homo, 233. 



Urochorda (wpa, the tail ; %oplv, a string), 341, 135. 

 Uropygium (olpovvyiov, oppovvytov, the tail of a bird or fish) The stumpy tail 



of the Pigeon, 229. 

 Urostyle (ovpa, a tail ; rrvXos, a pillar), in the Frog A bony unsegmented 



rod, forming the posterior part of the backbone, 183, 184. 

 Uterus The dilated part of an oviduct, 33, 43, 52, 207, 299, 334. 

 Uterus masculinus, in the male Rabbit A pouch on the dorsal side of the 



bladder, into which the vasa deferentia open, 298. 

 Utriculus (dim. of liter, a bag or vessel of skin) A sac-like central part of 



the membranous labyrinth, from which the semicircular canals take 



origin, 173, 219, 255, 304. 



