632 APPENDIX. 



Genus SUSANIA, Gray. 

 (Sub-fam. pleueobbanchhwe.) 



Mantle very large, broadly margining the foot, vesicular, 

 deeply notched in front ; frontal veil between the base of the 

 tentacles and mouth large and oblong; foot oblong, rather 

 narrow. Shell very small. 



Ex. S. testudinaria, Philippi, pi. 137, fig. 13. 



In this genus the mantle is notched in front, while in Pleuro- 

 branchus it is entire. 



Vol. ii. p. 52. Genus CERATODORIS. 



This genus was established by Dr. Gray upon Doris eolida 

 of Quoy and Gaimard, which is supposed by Mr. Alder to be a 

 young Idalia. 



Genus CHROMODORIS, Alder and Hancock. 

 (Sub-fam. doeidin^;.) 



Body sub-quadrangular. Dorsal tentacles laminated, retractile 

 within plain or margined cavities ; oral tentacles conical or tu- 

 bercular. Gills linear, pinnate. 



Ex. C. magnifica, Quoy and Gaimard. 



Tbe species upon which this genus is founded we had included 

 in Doriprismatica. 



Genus trevelyana, Kelaart. 



(Sub-fam. POLYCERIN.E.) 



Body narrow, elevated and inflated near the gills. Head 

 simple, rather produced and rounded ; tentacles short, conical, 

 pointed, non-retractile, without sheaths, the upper half indis- 

 tinctly laminated. Gills numerous, plumose, surrounding the 

 dorsal vent, without lateral appendages. Foot long and broad, 

 terminating posteriorly in a lancet-shaped point a short distance 

 from the body. 



Ex. T. Ceylonica, Kelaart, pi. 137, fig. 14. 



