258 8MARAGDINELLA. 



GRAY, Figs. 'Moll. Anim, iv, p. 95 (for G. viridis, glauca, smarag- 

 <////'/), 1850. Linteria A. AD., in Sowb., Thes. ii, p. 558 (1850). 

 Tkecaphorm NUTT. ins., fide Ads. 



Shell mainly external, oval, formed of little more than one whorl, 

 the entire interior visible from the open front and base. Apex con- 

 cealed. Aperture occupying nearly the whole ventral surface, ovate, 

 with a deep posterior sinus; columella long, curved, with a reflexed 

 adnate callus, the parietal wall bearing an oblique, curved, spirally 

 entering j>!<ite, which projects downward into the aperture. Type 

 N. riridis. 



Animal having a squarish frontal disc bearing well developed 

 eyes, and obsoletely bilobed behind ; foot about as long as the shell, 

 squarish-oblong ; epipodial (lateral) lobes well developed, partially 

 covering the shell. Stomach with cartilaginous plates. Dentition 

 unknown. 



Smaragdinella lives between tides, exposed to the waves. Its 

 green coloring assimilates the creature to its surroundings. Two 

 subgenera are recognized: SMARAGDINELLA Ad., shell oval, green. 

 (2) NONA Ads., shell white, subtrigonal, the lip more produced 

 above. 



S. VIRIDIS (Rang) Q. & G. PL 33, figs. 42, 45, 46, 47, 48, 49-53. 



Shell oval, solid, dark green, consisting of about Ii whorls; en- 

 tirely open from the front and base, the aperture occupying nearly 

 all of the ventral aspect; dorsal surface regularly rounded; apex 

 concealed, the vertex in some old shells marked by a tiny keel-encir- 

 cled cup ; sculptured with irregular growth lines. Aperture ovate, 

 having a narrow sinus behind, elsewhere broadly rounded. Outer 

 lip thin, rising somewhat above the vertex behind; columellar lip 

 arcuate, nearly as long as the shell, slightly thickened, and with a 

 reflexed adnate callus running backward to the vertex ; from this 

 callus springs a wide entering plate, spirally twisted into a saucer- 

 like process projecting into the aperture. 



Alt. 12, diam. 8i mill. 



Island of Bourbon ; J!'' union ; Gnmn ; Snmhrich Is. 



Bnl/'i riridis RANG, in Q, & G., Voy. Astrol. Zool. ii, p. 350 

 pi. 26, f. 13-16. Linteria riri'1!* Ai>. in The.-?. Condi, ii, p. .")!?. pi. 

 121, f. 52. SoWB. in C. Icon., f. 3. Snutraiflinel/a riridis Al>S., 

 Gen. Rec. Moll, ii, j>. 2M.--M AKTKNS, Donuin Bism., Summl. Su. !-<- 

 conch, j). '">.') ; Meeres-Fauna Maurit. etc., p. 304. Lintrrin <jl 



