GASTEROPODA. 335 



Animal elongated, smooth ; head covered with a veil ; tentacles 

 clavate, laminated, retractile into sheaths ; gills filamentose, 

 arranged along the sides of the back, on the wavy margins of 

 the mantle; foot narrow, with tentacular processes in frcnt; 

 stomach ramified. 



Distrilution, 3 species. Britain and Mediterranean. On 

 corallines. 



Family VIII. — ^^OLiDiE. 



Animal with papillose gills (?), arranged along the sides of the 

 back; tentacles sheathless, non-retractile ; lingual teeth 0.1.0; 

 ramifications of the stomach and liver extending into the dorsal 

 papillae ; excretory orifices on the right side ; skin smooth, with- 

 out spicula ; no distinct mantle. 



^OLis, Cuvier. 



Synonyms, Psiloceros, Menke. Eubranchus, Forbes. Ampho- 

 rina, Quatref. 



Type, ^. papillosa, L. 



Etymology, ^olis, daughter of ^olus. 



Animal ovate ; dorsal tentacles smooth, oval, slender ; papillse 

 simple, cylindrical, numerous, depressed, and imbricated ; mouth 

 with a horny upper jaw, consisting of two lateral plates, united 

 above by a ligament ; foot narrow ; tongue with a single series 

 of curved, pectinated teeth ; spawn of numerous waved coils. 



Sub-genera. Flahellina, Cuvier. (Phyllodesmium, Ehr.) Body 

 slender ; dorsal tentacles laminated, buccal long ; papillae 

 clustered ; spawn multi-spiral. Example, E. Coronata, PI. 

 XIII., Fig. 13 (also Fig. 11, p. lY). 



Cavolina, Brug. (Montagua, Flem.), C. peregrina. Body lan- 

 ceolate ; tentacles smooth or wrinkled ; papillae in transverse, 

 rather distant rows ; spawn of 1 or 2 coils. 



Facelina, Griibe. Like Flabellina, but with the foot small, 

 and the two front angular portions drawn out to a point. 



JDistrihution, 6 species. Sitka, North Sea. 



Coryphella, Landsborough. Like Cavolina, but with papillsC' 

 arranged in groups. 4 species. 



Tergipes, Cuvier, T. lacinulata. Body linear ; tentacles 

 smooth ; papillae in a single row on each side ; spawn kidney- 

 shaped. 



Distrihution, Norway, Britain (33 species). United States, 

 Mediterranean, South Atlantic, Pacific. Found amongst rocks at 

 low water ; they are active animals, moving their tentacles con- 

 tinually, and extending and contracting their papillae; they swim 



