148 PEDUNCULATA. 



CLASS III.— CIRRIPEDA. 



The animals are soft, destitute of head or eyes, covered with 

 a shell, which is fixed to other substances, and incapable of lo- 

 comotion. The body is inarticulated, provided with a mantle, 

 having tentacular, cirrous, or many-pointed arms or feelers 

 above. 



The class Cirripeda is divided by Lamark into two orders :— 

 I. Pedunculata. The body supported by a tubular moveable 

 peduncle, the base of which is attached to extraneous substances 

 in the ocean, such as stones, wood, &c. ; the mouth is usually 

 placed below. — II. Sessilia. The body without a peduncle, 

 and attached to extraneous substances; the mouth usually at 

 the top. 



All the Cirripeda are multivalve, or composed of a number 

 of pieces. 



ORDER I.— PEDUNCULATA. 



Body supported on a tubular peduncle. 



Genus \ — OTION.— Zeac/z. 



Generic Character. — Body pedunculated, enveloped in a mem- 

 branous tunic, which is ventricose above ; two horn-like tubes, 

 directed backwards, truncated, and open at their points, and 

 situated in the apex of the tunic ; having a lateral opening, with 

 many articulated and ciliated arms. — Shell consisting of two 

 small testaceous semilunar valves, attached near the lateral open- 

 ing. 



Oiion B/ainuiffii.— Blainville's Otion. Plate XIX. fig. 

 1, Ash-coloured : the body and horns spotted with black. In- 

 habits the North seas. 



Genus 2— CINE HAS.— ZeacA. 

 Generic Character.— Body pedunculated, and encased in a 



