H-S ZOOLOGY. 



have been divided into the siphonostoma and the lernea ; the 

 first have always swimming limbs, and attach themselves by 

 means of limb-jaws having the form of hooks; the second, on 

 reaching the adult age. present no longer any traces of loco- 

 motory organs, and have often been confounded with the 

 intestinal worms.* 



580. It is also in this division of the entomostraca that 

 we must arrange the cirrhopoda, which at first sight seem to 

 have many analogies with the mollusca, more so indeed than 

 with animals of the class we now describe ; but in fact they 

 are only Crustacea with the body deformed after they have 



Fig. 435. Anatifse. 



ceased to lead a wandering life. When young, these small 

 beings, which are all marine, swim freely, and resemble 

 extremely certain ordinary en tomostraca, such as the young 

 cyclops (Fig. 135) ; but soon afterwards they become fixed, 



' A species of lernea attacks the gills of the salmon during its residence in 



rr.'-li \\ati-rs, l>ut seems to perish wht-n tin- fi-h r.-turn t> tin- sea. K. K. 



