216 systematic arrangement 



1. Ceratosoma. 



Back produced into a conical prominence behind. Tentacles in 

 mantle. Gills plumose, retractile into a cavity. Mouth subretrac- 

 tile. Teeth in many lines, diverging from the centre. 



1. C. trilobata, t. 67. f. 14, t. 214. f. 7. 



Suborder II. Inferobranchia. 

 Gills on the under side of the expanded mantle, lamellar. 



Fam. VII. PHYLLIDlADiE. 



Dorsal tentacles laminated, retractile within cavities in the cloak. 

 Labial palpi close, conical, small. Gills in the form of radiating folds 

 on the under side, within the edge of the mantle, surrounding the 

 body, interrupted only by the head. Vent medial, postero-dorsal. 

 Cloak large, spinulose, covering the whole body, tuberculated or pus- 

 tulated. Jaws and tongue none. 



1. Phyllidia. 

 Vent dorsal, in the middle of the hinder part of the back. 



1. P. ocellata, t. 312. f. 8. 



2. P. trilineata, t. 312. f. 3, 4, 6, 7. 



3. P. albo-nigra, t. 312. f. 2. 



4. P. annulata, Gray, Ann. fy Mag. Nat. Hist. 1853, 221. 



2. Fryeria. 



Vent in the middle of the hinder part, in the groove between the 

 mantle and the foot. 



1. F. pustulosa, t. 312. f. 1, 5. 



3. Hypobranchi^ea. 



Vent ? Gills ? 



1. H. fusca, t. 220. f. 1. 



Fam. VIII. DIPHYLLIDIADiE. 



Mantle large, bent up on the sides. Dorsal tentacles two, simple, 

 situated in front of the cloak, with a veil above the head. Gills 

 in folds on the under side of the edge of the mantle, which is 

 bent up. Jaws horny. Anus lateral. Digestive organs with a 

 rudimentary gastro-hepatic system. 



