336 MANTAL OF THE MOLLTTSCA. 



readily at tlie surface, inverted. They feed chiefly on sertnlarian 

 zoophytes, and if kept fasting will devour each other; when 

 irritated they discharge a milky fluid from their papillae, which 

 are very liable to fall off. 



Glatjctjs, Forster. 



Etymology, glaucus, a sea-deity. 



Synonyms, Laniogerus, Bl. Pleuropus, Eaf. 



Example, Or. Atlanticus, PI. XIIL, Fig. 14. 



Animal elongated, slender ; foot linear, channeled ; tentacles 

 4, conical ; jaws horny ; teeth in single series, arched and 

 pectinated; gills slender, cylindrical, supported on 3 pairs of 

 lateral lobes; stomach giving off large coeca to the tail and 

 side lobes ; liver contained in the papillae ; sexual orifice 

 beneath first dextral papilla, vent behind second papilla; 

 spawn in a close spiral coil. 



Distribution, 7 species. Atlantic, Pacific. Pound on floating 

 sea- weed; devours small sea-jellies, Forjpitce and Velellce, 

 (Bennet.) 



PiONA, Alder and Hancock. 



Type, P. nobilis, A. and H. 



Synonym, Oithona, A. and H. (not Baird). 



Animal elongated; oral and dorsal tentacles linear; mouth, 

 armed with horny jaws ; gills (?) papillary, clothing irregularly 

 a sub-pallial expansion on the sides of the back, each with a 

 membranous fringe running down its inner side. 



Distribution, 3 species. Palmouth. Under stones at low 

 water. (Dr. Cocks.) 



Embletonia, a. and H. 



Etymology, dedicated to Dr. Embleton, of Newcastle. 



Synonyms, Pterochilus, A. and H. ? Cloelia (formosa), Loven. 



Type, E. pulchra, PI. XIIL, Pig. 15. 



Animal slender; tentacles 2, simple; head produced into a 

 flat lobe on each side; papillae simple, sub-cylindrical, in a 

 single row down each side of the back. 



Distribution, 4 species. Scotland (2 species). In the littoral 

 and laminarian zones. 



Calliopcea, (bellula), D'Orbigny. Brest ; has 2 rows of papiEsB 

 down each side of the back; cephalic lobes subulate; vent 

 dextral. Lon. 3 lines. 



