18 



CLASS-BOOK OF ZOOLOGT. 



IV. Ichthyology. 



Fig. 4. 



The Tench. — (Tinea vulgaris?) 



V. Entomology. 



Fig. 5. 



The Rover-Beetle. — (Stapliylinus olens.) 



VI. Helminthology. 



Fig.' 



© 



'The Leech. — (Hirudo medicinalis.) 



