CLASS CRUSTACEA: ORDER CIRRIPEDIA. 



233 



ORDER SIPHONOSTOMA. 



General Characteristics. The Siphonostoma (suck- 

 ing-month) in their early stages have eyes, jointed limbs, 

 and swim freely, but when adult they are attached to fish, 

 and live mainly on the mucus which covers their host. A 

 permanent hold is secured by insinuating their barb-like 

 head into the flesh, often the eye. (Fig. 397.) 



Fig. 897. 



Fig. 



LernceoriZma spratti, 

 Sprat-sucker, attached to eye of Sprat. 



Baldnus crenatw, Acorn Barnacle. 



ORDER CIRRIPEDIA. 



General Characteristics. The Cirripeds (curl-footed) 

 in their early stages have eyes, antennae, and limbs. After 

 swimming about for a while they attach themselves to any 

 solid substance, the eyes become rudimentary and the 

 antennae obsolete. The thoracic feet by constant motion 

 create currents of water which float food to the animal's 

 mouth. 



Balanidae. The Acorn Barnacle is sessile, the shell 



