572 GLOSSARY 



Tympanic (tim-pan'-ik), refers to the cavity of the middle ear. 



Typhlosole (tif'-lo-sol), a dorsal fold of the intestine, as found in the earthworm. 



Ulna (ul'-na), the longer bone of the forearm. 



Umbilical (um-bir-I-kal), pertaining to the umbilicus; the region where the 



embryo forms a connection to the embryonic membranes. 

 Umbo (um'-bo), a hump found on bivalved mollusk shells near the hinge. 

 Ureter (u-re'-ter), an excretory tube leading from the kidney to the bladder. 

 Urethra (u-re'-thra), tube leading from the bladder to an external urinary 



opening. 

 Urogenital (u-ro-jen'-i-tal), pertaining to both excretory and reproductive 



systems. 

 Urostyle (ur-o-stil'), the posterior portion of the vertebral column of the frog, 



formed by fusion of caudal vertebra. 



Vacuole (vak'-u-ol), a vesicle of non-living liquid material within the cell. 

 Vagina (va-ji'-na), the cavity between the uterus and the external genital 



opening of the female of many animals. 

 Vas deferens (vas def'-er-ens), pi. vasa deferentia (vas'-a def-er-en'-ti-a), tubes 



that carry the sperm in the male reproductive system. 

 Vas efferens (vas ef'-fer-ens), pi. vasa efiferentia (vas'-a ef-er-en'-ti-a), small 



tubules that collect the sperm from the testes and transfer them to the 



vas deferens. 

 Velum (vel'-um), a membrane found on the subumbrella surface of some 



jellyfish. 

 Ventricle (ven'-tn-kl), a chamber of the heart that pumps blood from the heart. 

 Vertebra (ver'-te-bra), a bone of the vertebral column. 

 Visceral (vis'-er-al), referring to the internal organs. 

 Viviparous (vi-vip'-a-rus), placental, live-bearing reproduction. 



Zoogeography (zo-o-ge-og'-ra-fi), a study of animal distribution. 



Zoology (zo-ol'-o-jT), the science dealing with animal life. 



Zygote (zi'-g5t), a cell formed by the union of gametes of opposite sexes. 



