RHABDOPLEURID.^. 677 



Subclass Pterobranchia, E. Kay Lankester. 



AsPiDOPHORA, AUman, Journ. Lion. Soc. Zool. xiv. 1879. 



Order PODOSTOMATA, Lankester. 

 Foot large, discoid, overhanging the mouth. 



Family EhabdopleuridaB. 



ZoARiuM a chitinous, adherent tube, divided by septa into 

 compartments, from which erect tubular cells rise, in 

 lohich the polypides are lodged ; the whole of the ad- 

 herent portions traversed by a chitinous cylindrical 

 rod, to which the polypides are attached by means of a 

 flexible cord; endocyst not differentiated, and the poly- 

 pide consequently unattached to its cell ; retractor and 

 other muscles absent ; a large, shield-like organ (foot) 

 placed near the mouth ; the young (bud) furnished with 

 two valve-like fleshy plates. 



Genus RHABDOPLEURA, AUman. 



Der. From pdjSSos, rod, and TrXevpa, side. 



Rhabdopleura, AUman (1867). 

 Halilopiius, M. Sars (1868)*. 



The only genus. 



Op this remarkable form, which constitutes the type of 



* ' Forsatte BemEerkninger om det dyriske Livs Udbredning i Havets 

 Dybder,' p. 12. 



2p 



