CIRRHIPEDA. 



43 



be exceeding rapid. A ship going out with a 

 perfectly clean bottom, will often return, after 

 a short voyage, covered with them."* 



20. Scalpellum (Leach). — Shell 

 composed of thirteen unequal pieces, 

 twelve of which are lateral and very 

 much flattened or compressed, and one 

 of which is dorsal, elongated, and 

 acuminated at the base. They are 

 all united together on the integument, and the 

 peduncle is covered with small scales. Animal 

 resembling the Anatifa. — 2 species. 



21. Pollicipes. — Shell com- 

 pressed at the sides, valves rather 

 contiguous, unequal, thirteen or 

 more in number, the lower side 

 valves the smallest; peduncle 

 short and wrinkled. Animal like 

 the Anatifa. — 10 species, recent and fossil. 



Found in the Northern and European Seas, 

 in groups upon rocks. 



22. Cikeras. — Shell composed of five tes- 

 taceous oblong valves, separate, and not cover- 



* Penny Cyclopaedia, art. Cirrhipeda. 



