354 TORNATELLID^. 



and on rocks weeping fresh water near the sea-shore. Both 

 animal and shell are of a glaucous green color. 



NONA, H. and A. Adams. Shell white, fragile ; outer lip pro- 

 duced into a wing behind. L. Algirse (Ixxxvii, 22). 



Scaphander, Montfort. 



Etyra. — Scaphe, boat, aner, man. 



Distr. — 13 sp. United States, Norway, Britain, Mediterra- 

 nean on sandy ground, 50 fathoms. Fossil, 8 sp. Eocene^ — . 

 S. ligiiarius, Linn. (Ixxxvii, 23). 



Shell oblong, convolute ; spirally striated ; aperture much 

 expanded in front ; spire concealed ; epidermis thick ; lingual 

 teeth l-O'l, crested. 



Animal with a large oblong head, destitute of eyes ; foot short 

 and broad ; lateral lobes reflected, but not enveloping the shell ; 

 gizzard with two large trigonal plates and a small narrow trans- 

 verse plate. It feeds on Dentalium entale. 



Aglaia, Renier. 



Syn. — Accra, Cuvier. Eidothea, Risso. Doridium, Meckel. 



Distr. — 3 sp. South Europe. D. membranaceum^ Meek. 

 Mediterranean. 



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, mem,- 

 branous shell. 



Gastropteron, Meckel. 



Distr. — G. Meckelii, Bl. (Ixxxvii, 24). Mediterranean. 



Animal oval, with side-lobes developed into wing-like expan- 

 sions, 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 gill, excretory opening behind 

 it. Shell almost microscopic. 



[Atlas, Lesueur. 

 Referred to this family by several systematists, is a larval 

 creature, and not of a mollusk — Macdonald.] 



Family TORN ATELLIDJi:. 



Animal generally perfectly retractile, but mostly of large size 

 When expanded ; foot thick, reflexed on the sides; head broad, 

 very often forming a flat disk, with or without other appendages ; 

 tentacles broad, thick, united at base ; eyes sessile near the base. 

 Dentition, laterals numerous, uniform, in diverging cross series, 

 rachidian teeth wanting (xiii, 68). 



