Suborder I. PELLIBEANCHIATA. 



Without special gills : skin without spicula. 



This group was first described as a distinct order by Alder 

 and Hancock in the ' Annals of Natural History ' for June 

 1848 ; it is now proposed to consider it a suborder of Nu- 

 dibranchiata. It forms, however, an aberrant member of that 

 order, the animals being of very simple structure, and possess- 

 ing none of the variety and beauty of form, and little of the 

 brilliancy of colouring, that are usually found in the N"udi- 

 branchs. M. de Quatrefages united these animals with the 

 Eolodidce in his order of Phlebenterata ; but the relationship 

 between them is not so close, nor the organization of either 

 group so low, as was supposed to be the case by that distin- 

 guished naturalist. 



Family I. LIMAPONTI'ID.^, Alder and 

 Hancock. 



Without mantle or appendages : tentacles 2 or wanting : vent 

 posterior : odontophore denticulated ; no jaws. 



Genus I. LliMAPON'TIA*, Johnston. 

 [PL I. f. 5.] 



BODY limaciform, simple, without tentacles : vent dorsal and 

 posterior : odontophore narrow, with a single row of spines. 



Chalidis of Quatrefages is probably synonymous with this 

 genus. [Pontolimaoc, Creplin.] 



1. LIMAPONTIA NIGRAJ Johnston. 



L. nigra, Johnst. in London's Mag. N. H. ix. p. 79 ; A. & H. in Ann. N. H. 

 2nd ser. i. p. 402, pi. 19. f. 4-8. 



BODY smooth, rather depressed, nearly linear when extended, 

 * From Imax, a slug, and pontus, the sea. 



