94 HELIX-HELENOCONCHA. 



The species to which the foregoing remarks apply is certainly the 

 Helix alexandri of Forbes, for in the British Museum there are spec- 

 imens of it presented by Mr. Alexander, who also furnished Forbes 

 with the shells he described. Moreover the description is fairly 

 applicable, especially that portion of it referring to the umbilicus, 

 which is described as " maximus." It is much less certain that this 

 is the H. polyodon of Sowerby, but as Mr. Wollastou has united 

 these species as well as H. helenensis (Forbes) Pfeiff'er, it will prob- 

 ably be advisable to acquiesce in this decision. There are however, 

 certain differences in the descriptions, which seem to indicate that 

 more than one species was described by these authors, for instance : 

 H. polyodon is said to consist of six striated whorls, with three 

 parietal and five palatal lirse, and a moderate sized umbilicus, 

 whereas H. alexandri is described as having seven strongly striated 

 whorls, three parietal and eight palatal lirse, and a very large um- 

 bilicus. H. helenensis is characterized as possessing eight very nar- 

 row closely costate whorls, and only two parietal lirse and the same 

 number within the outer lip. Pfeiffer states that H. helenensis was 

 described by Forbes in the Proc. Zool. Soc. for 1851, and this state- 

 ment is copied both by Keeve and Wollaston. This appears to be 

 an error, for after a careful search, I have been unable to discover 

 in any publication the description by Forbes of any species of Helix 

 under that name. (Smith.} 



P. MINUTISSIMA Smith. PI. 36, figs. 23, 24, 25, 26. 



Shell conoid-depressed, moderately widely umbilicated, maculated 

 and variegated with white and reddish ; spire slightly elevated, 

 obtuse above ; whorls 7, the earlier two smooth, pale rufescent, the 

 rest slightly convex, ornamented with delicate, oblique, arcuate liru- 

 lae, flexuous on the last whorl, which is rounded or sometimes 

 obsoletely angled at the periphery, hardly descending in front. 

 Aperture oblique, semi-lunate; parietal lamellre 6 in mature, 4 or 5 

 in younger shells ; palatal plicae 8-10 ; peristome thin, columellar 

 margin expanded. Alt. 2}, greater diam. 41, lesser 4 mill. (Sin.') 



Sugar loaf Ridge, St. Helena (extinct). 



Patula (Endodonia) minutissima SMITH, P. Z. S. 1892, p. 264, t. 

 21, f. 9-9c. 



This species is smaller than P. polyodon, more narrowly umbili- 

 cated, has fewer whorls, coarser and more remote stride, and a dif- 

 ferent armature within the aperture. In full-grown shells there are 



