200 



HIGH SCHOOL ZOOLOGY. 



mucli the creatures they attack, but one fonu, Anjulus, which 

 attains the length of quarter of an inch, is found to kill the 

 wliitefish in lakes in the North-West in immense numbers. 



Fig. 128.— Ci/ctopssp. x 12. 



Fig. 120. -Erijasilua 

 with egg-sacs from 

 gills of sunfish xiu 



Fig. 130.— Ach- 

 thercs from gills 

 of catfish X 6. 



This form attaches itself by the anterior foot-jaws, which are 

 modified into suckers, but it is the piercing and sucking mouth 

 which injures the fish. 



The remaining oi'der — the Cirri- 

 pedia — lias only marine forms, which 

 pass through an active larval phase, 

 but eventually attach themselves by 

 their heads and secrete a compli- 

 cated shell (Figs. 131 and 132). The 

 antennae are rudimentary, but thi-ee 

 pairs of jaws are present, and behind 

 these, six parrs of biramous feet, 

 which by their movements bi-ing food 



particles to the 



mouth. These are, 



however, absent in 



certain parasitic 



forms. 



Fig. 131. — Shell of Bnlanim hamrri. 



Fig. 132. -Lcpa.f unutifera. 



