CIRIlIIOrODA; BARNACLE, ETC. 



283 



III. APODA, with the same number of segments as the pre- 

 ceding, but without any cirri, and with no distinct carapace. 



896. The section THORACICA, which includes all the Cirrho- 

 poda known until the publication of Mr. Darwin's important 

 work, is again divisible into two very distinct families. The first 

 of these, the LEPADID^E or PEDUNCULATA, including the LEPAS 

 or BARNACLE and its allies, consists of those Cirrhopods which 

 are attached by a long fleshy peduncle or footstalk ; their form 

 is flattened at the sides; and the opening through which the cirri 

 are protruded is along one edge. The capitulum or body of the 

 animal, as opposed to the peduncle, is sometimes entirely mem- 

 branous, but usually inclosed in a shelly carapace composed of 

 five or more valves, connected by strips of membrane. Of this 



FIG. 616. CONCHODERMA CRANCHI1. 



FIG. 615. Group of BARNACLES, attached to a ship's 

 bcttom. 



family some species are common in nearly all seas. Most of 

 them fix themselves to wood in preference to anything else ; so 



