412 



MOLLUSCA. 



Fam. 2. Scyllaeidae. Anterior tentacles absent ; two pairs of large folia- 

 ceous cerata ; foot narrow. Scyllaea L., on floating seaweed. 



Fam. 3. Phyllirhoidae. Anterior tentacles and cerata absent. Body com- 

 pressed laterally, without foot. Stomach with caeca. Orifices on the right 

 side. With fin -like tail. Transparent. Pelagic. Phyllirhoe Per. et Les. 

 (Fig. 326). 



Fam. 4. Tethyidae. Anterior tentacles absent ; rhinophores conical ; head 

 surrounded by a funnel -like velum ; cerata foliaceous ; foot large ; radula 

 absent. Tethys L. Melibe Rang. Cerata of Tethys are capable of independent 

 movement after separation. 



Fam. 5. Dendronotidae. Tentacles forming a fringed frontal velum ; cerata 

 branched ; rhinophores arborescent ; radula 10 : 1 : 10 ; liver extending into the 

 cerata. Dendronotus A. and H. ; Hero Loven ; Lomanotus Verany. 



Tribe 2. DORIDIOIDEA. 



Liver not branched ; anus median posterior, generally dorsal and surrounded 

 by ramified appendages the cerata or branchiae. Genital ducts triaulic. 

 Spicules in the mantle. 



Fam. 1. Polyceridae. A frontal velum more or less projecting. Branchiae 

 non-retractile. Ehinophores foliate. Euplocamus Philippi ; Triopct Johnston ; 

 Polycera Cuv. ; Ancula Loven ; Goniodoris Forbes ; Idalia Leuckart ; Hetero- 

 doris Verril and Emerton ; Aegirus Loven ; Acanthodoris Grube. 



Fam. 2. Dorididae. Mantle covering the head ; anterior tentacles small ; 

 rhinophores foliate ; branchiae retractile into a perianal pocket. Doris L. ; 

 Chromodoris A. and H. ; Hcxabranchus Elirbg. 



Fam. 3. Doridopsidae. Doris-like, but mouth 

 suctorial, without radula. Doridopsis A. and H. 



Fam. 4. Corambidae. Doris-like, but anus and 

 branchiae behind, below the edge of the mantle. 

 Corambe Bergh. 



Fam. 5. Phyllidiidae. Mouth suctorial ; no 

 radula ; branchiae all round the body between the 

 mantle and the foot. Phyllidia Cuvier. 



Tribe 3. AEOLIDIOIDEA. 



The liver caeca extend into the cerata, which often 

 contain nematocysts. Genital duct diaulic, with 

 contiguous male and female openings. Jaws are 

 present. 



Fam. 1. Aeolididae. Cerata terminating in open 

 sacs (Fig. 329), which communicate with the hepatic 

 caeca and give origin by their lining epithelium to 

 nematocysts (Fig. 330). Aeolis Cuvier (Fig. 323). 



Fam. 2. Glaucidae. With three pairs of lateral 

 lobes (cerata) carrying tegumentary papillae. Foot 

 narrow. Glaucus Forster. 



Fam. 3. Pleurophyllidiidae. Anterior tentacles constitute a burrowing shield. 

 Branchiae beneath the edge of the mantle ; radula 30 : 1 : 30. Pleurophyllidia 

 Meckel (Fig. 331) ; Dermatobranchus Van Hasselt. 



Fam. 4. Dotonidae. Cerata tuberculated, without nematocysts, and in one 

 row on each side. Doto Oken. 



FIG. 327. Doris pilosa 

 (after Alder and Han- 

 cock). Br gills ; A anus ; 

 F tentacle. 



