356 MALENTOZOA. PEDUNCULATA. 



to six transversely striated ribs, the depressed areas tri- 

 angular, finely striated transversely. Balce?idris, at- 

 tached to whales. 



ORDER I.— MALENTOZOA PEDUNCULATA. 



The mantle prolonged beneath, so as to form a fleshy 

 contractile peduncle. 



The species adhere to timber, ships, and other objects, 



floating on the sea, or to fixed submersed substances, as 



corallines or shells ; but are very uncommon on our 



coasts, although plentiful on the west side of Scotland. 



Family I. — Lepamna. 



Animal oval or oblong, much compressed, suspended 

 in its testaceous envelope, to which it adheres by a 

 transverse muscle situated near the aperture ; mantle 

 open behind only, and at the other end prolonged to 

 form a fleshy contractile stalk, which adheres to sub- 

 marine bodies ; branchiae numerous, pyramidal, at the 

 base of the lower cirri. 



Sometimes the mantle almost or entirely cartilaginous, 

 but generally covered with five testaceous plates of a 

 triangular form ; two large superior lateral, receiving the 

 transverse muscle, two smaller lateral, and a narrow 

 medial piece connecting the rest ; but often a greater or 

 less number of accessory pieces at the base. 



These animals, essentially carnivorous, seize their prey 

 by means of the articulated appendages with which the 

 hind part of the body is furnished. 



Genus 1. Lepas. Barnacle. 



Animal ovate or subtriangular, compressed, enveloped 

 in a very thin mantle ; cirri curved at the end, in twelve 

 pairs ; peduncle fleshy. 



Shell subtriangular, formed of four lateral pieces, and 

 an elongated dorsal piece, completely covering the mantle; 

 operculum quadrivalve. 



