APPENDIX. 279 



height (the dorsal length of the penult being to the breadth of 

 it as three to five). The sculpture consists, upon the penult and 

 preceding turn, for the first coil and a half do not exhibit any, of 

 either narrow prominent and distant, or broad depressed and 

 approximate, yet never very numerous, perpendicular ribs, whose 

 intervals are clathrated by two spiral costellar lines, that wind 

 along the lower half of each whorl. A third revolving line suc- 

 ceeds them upon the rather narrow body- whorl, beyond which the 

 ribs, that finally become rather more closely disposed, extend some 

 little distance ; the base itself, however, is smooth, or almost so 

 (always devoid, at least, of spiral striation), and is rounded yet 

 rather quick in its declination. The mouth, which occupies two- 

 fifths, at least, of the entire length, is simply ovate ; it is not 

 distinguished by any peculiar markings. The outer lip is thin, 

 simple, arcuated, and moderately projecting ; it neither expands, 

 nor does it advance much at the base, where there seems occa- 

 sionally a slight disposition to effusion. The curved pillar lip, 

 which is acute and rather elongated, curls very slightly back, but 

 is not reflected, nor furnished with a distinct fold. The axis is 

 most minutely subperforated. The length of this minute shell is 

 but a single line, which is about twice its extreme breadth. The 

 discovery of this species is due to Mr. Barlee, who obtained it in 

 the Zetland Islands. 



Vol. iii. p. 276. Odostomia ditbia. 



This species was erroneously named unidentata. var. upon the 

 plate (XCIV. fig. 8). We do not like the figure. 



Vol. iii. p. 284. Odostomia Rissoides. 



The animal is described by Mr. Clark in the " Annals of Na- 

 tural History," for December, 1850. The tentacles are very 

 short, broad, awl-shaped, bevelled and blunt, and are marked from 

 base to point by an opaque linear stripe, besides a white dot at 

 their tips. The eyes are large, black, and immersed at the internal 

 bases of the tentacles. The foot is very short, truncate, and 

 scarcely auricled in front, pointed (when on the march) behind. 



