GASTEROPODA. 3l9 



o]blong ; eyeless ; foot broad ; lateral lobes large, but not 

 enveloping ; tongue vdth. two or four series of sickle-sbaped 

 uncini ; gizzard with tliree longitudinal shelly plates. Egg 



are- _^^ 



Fig. 138. Philine aperta.* 



capsules ovate, in single series on a long spiral thread; fiy 

 with a ciliated head-yeil and an operculated, spiral shell. 

 (Lo"ven.) 



Distribution, 16 species. West Indies, Greenland, Norway, 

 Britain, Mediterranean, Corea, Borneo. 



Fossil, 7 species. Eocene — . France. 



Suh-gem/.s. Chelidonura, A. Adams, (Hirundella, Gray) B. 

 hirundinaria, Quoy, Mauritius. Shell concealed; outer lip 

 produced posteriorly into a spur; columellar : border inflected. 

 Animal with enveloping side-lobes ; mantle with two appendages 

 behind, like the lateral processes of Hyalaea. 



DoEiDiTJiT, Meckel. 



Etymology, diminutive of Doris. 



Synonym, Accra, Cuvier. Eidothea, Eisso. 



Type, D. membranaceum, Meek. Mediterranean. 



Distribution, 3 species. South Europe. 



Animal oblong, truncated behind, the angles produced and 

 dilated or filiform ; head ovate-oblong, retuse in front ; side- 

 lobes expanded, wing-like; mantle investing a rudimentary, 

 membranous shell. 



Gasteopteeon, Meckel. 



Type, G. Meckelii, Bl. (Clio amate, Chiaje) Mediterranean. 



Animal shell-less, oval, with side-lobes developed into wing- 

 like expansions, meeting and uniting behind; cephalic disk 

 triangular, obtuse in front, pointed behind, eyes centrally 

 immersed; lingual teeth 5.1.5; mantle? branchial plume 

 exposed on the right side ; reproductive orifice in front of the 



* From a specimen dredged at Folkestone ; o, mouth ; c, head, or cephalic disc, 

 I, side-lobes of the foot; m, mantle. The shell s, and gizzard g, are indistinctly seen 

 tlnough the translucent integimaents. 



