44 GENA. 



columellar margin is slightly bowed or concave ; the lip margin 

 is not bowed, but in one plane ; so that when lying on its face the 

 peristome is in contact with a plane surface all the way around 

 except the median part of the columellar lip ; whilst in other polished 

 species the extremities alone support it, both lips being bowed. 



G. LENTRICULA A. Adams. PL 55, fig. 14. 



Shell haliotoid, oblong, back convex, all over very delicately 

 striated, thin, fragile, flesh-colored, spotted with red ; spire nearly 

 terminal, small, laterally inclined ; aperture open, very much 

 lengthened. (Ad.) 



Calapan, Island of Mindoro, Philippines ; in 9 fms- 



G. lentricula AD., P. Z. S. 1850, p. 38 ; Thes. Conch, ii, p. 830, t. 

 173, f. 22. 



G. LUTEA (Linn.) Adams. PI. 2, figs. 29, 30, 31; pi. 55, figs. 8, 9. 



Shell Haliotis-shaped, quite convex, variegated white and pink- 

 ish-brown ; surface polished ; outer lip sinuous ; shell resting on the 

 two ends only when placed upon a plane. 



In shape it is shorter than G. auricula, with the outer lip more 

 sinuous and more bowed. Surface polished, showing radiating 

 growth-striae above, under a lens, and close microscopic spiral stria? 

 on the base, the beginning of the last, and the earlier whorls. The color 

 is a brownish pink, mottled and lineolate throughout with white. 

 Aperture oblong, silvery within and iridescent ; outer lip sinuous, 

 columella arcuate. 



Length 13J, breadth 8, convexity 4? mill.; aperture, length 11, 

 breadth 7 mill. 



East Indies. 



Gena lutea Linn. A. ADAMS, in Thes. Conch, ii, p. 828, t. 173, f. 

 4, 5. (? Patella lutea Linn., Syst. Nat. x, p. 783.) 



I can but agree with Hanley that the Patella lutea of Linne is 

 unidentifiable. The shell described above, and figured on pi. 2, figs. 

 29-31, is, I believe, the G. lutea of Adams. It is a less lengthened 

 species than G. auricula, and the lips are so curved that the shell is 

 supported by the ends alone when placed face down upon a plane. 

 It is much more convex than G. rosacea, Icevis, or caledonica, and 

 does not have the faint shoulder carina of the first two. I do not 

 know what relation exists between this and the next species, tor 

 while Adams says it is easily distinguished from that form, he does 

 not tell the differences. 



