82 



ANATIFA BALANUS. 



Fig. 71. 



ANATIFA. 



They have a heart, which is placed on the dorsal part of the 

 body, and they breathe by branchiae, the form of which varies. 



23. The Cirrhopods are divided into two natural 

 families: the ANATIFJE, which are fixed by a 

 long cylindrical peduncle, and the BALANI, which 

 are without a similar peduncle. 



24. The Anatifse, known in common parlance 

 as barnacles (Jigs. 70 and 71), are enclosed in 

 a sort of compressed mantle, open on one side, 

 and suspended from a fleshy tube ; sometimes 

 this mantle is almost entirely cartilaginous, and 

 is only furnished with two very small valves 

 (as in the genus Otion} ; at other times, as in 

 the genus ANATIFA, properly so called, it is 

 covered by five testaceous plates, the two largest 

 of which resemble those of a mussel. The 

 branchiae, which are in form of small pyramids, 

 are attached to the base of the cirri. The com- 

 mon Anatifa inhabits the Atlantic Ocean, and is 



frequently found attached to rocks, the bottoms of ships, or pieces of 



floating timber. It was the subject 

 of a most absurd fable ; from some 

 remote resemblance of its shell to a 

 bird, it was supposed to give origin 

 to a species of duck, and from this 

 it has obtained the name Anatifa 

 (from the Greek, anas, a duck). 



25. The Balani Balanus (fig. 

 72) abound on rocks in warm 

 regions of the ocean, and are entire- 

 ly contained in a very short, conical 

 shell, attached firmly* by the base, 

 and composed of several pieces 

 joined together; the opening of this 

 tube is occupied by from two to four 

 movable valves, between which we 

 find a slit which gives passage to 

 the cirri. The branchise are in 

 form of membranous, foliated and 

 fringed plates ; they adhere to the 



internal face of a sort of mantle which lines the shell. 



23. How are Cirr'hopods divided ? 



24. What are the characters of Ana'tifce ? 



25. What are the characters of Bala'ni ? 



ig. 72. GIANT BALANUS. 



