116 Elementary Manual of Zoology. 
Aortic arck.—A large artery which conveys the blood from the heart 
towards the back in Vertebrata. 
Asexual.— Without the intervention of the male. 
Auditory.—Connected with hearing. 
Auricle.—A thin walled chamber of the heart in Vertebrata. 
Barbels.—Slender feeler like organs situated about the mouth in many 
fishes. 
Bilaterally symmetrical.—With body arranged in such a manner around 
a central axis that the two sides are similar to each other, but the 
back (dorsal surface) is different from the front (ventral surface). 
Branchia.—Leaf-like respiratory organs adapted for breathing oxygen 
dissolved in water. 
Canines.—A pair of teeth situated one on each side of the mouth in 
~ Mammalia. 
Carabid,—Belonging to the group Carabide. 
Caudal.—Relatiug to the tail, 
Celit.—The ultimate living unit of which the body is built up. In 
its simplest form it consists of a little speck of protoplasm con- 
taining a nucleus. 
Cephalice.—Connected with the head. 
Cephalothoraz.—A division of the body composed of the head and 
thorax combined. It occurs in spiders and many crustacea. 
Chitin.—The substance of which the armour plates in insects are 
composed. 
Chitinous.—Formed of chitin. 
Chrysalis—The ‘name popularly given to the pupa in the group 
Lepidoptera on account of the golden coloration noticeable in 
certain species. : 
Ciltia.— Little vibratile hair-like processes attached to cells, 
Ciliated.— Furnished with cilia. 
Celomate.—Provided with a body cavity in which the digestive tract 
is suspended. 
Coleopterous,—Belonging to the group Coleoptera. 
Dermal.—Connected with the skin. 
Digestive tract.—The organs of the body which serve to take up 
nutriment direct from the food. 
Digitigrade.— Walking upon the tips of the toes, 
Dipterous.—Belonging to the group Diptera. 
Dorsal.—Relating to the back or upper surface of the body. 
Liytra.—tThe stiff horny front wings in beetles, 
Epidermis.—One of the layers of the skin in Vertebrata. 
Eacretory.—Connected with the casting off of waste products. 
Femur.—One of the joints of the leg. 
