224 HBLICIDjE. 



Helix ( Vallonia} pulchella, von Martens, Die Heliceen, ed. 2, 1860, 

 p. 101 ; Nevill, Hand List, i, 1878, p. 75. 



Vallonia pulchella, W. G. Binney, Terr. Moll. United States, v, 

 1878, p. 344, pi. 17, fig. 1 ; Theobald, J. A. S. B. xlvii, 1878, 

 p. 144 ; Sterki, Proc. Acad. Nat. Sci. Philadelphia, 1893, p. 246, 

 pi. 8, figs. A, G (radula), H, I, K, L (jaw) ; ibid., Man. Conch, 

 ser. 2, viii, 1893, p. 248, pi. 32, figs. 1-5 ; Pilsbry, op. cit. ix, 

 1895, p. 283, pi. 55, figs. 31, 32. 



Original description : " Helix testa umbilicata, subdepressa, 

 alba, glabra, apertura circinnata ; labro tereti, reflexo. 



" Testa tota alba, glabra, subpellucida, supra planiuscula, subtus 

 aliquantum convexa. Vertex testae, durn limax earn inhabitat, 

 luteolus. Anfractus vix quatuor, subtus unicus. Apertura fere 

 circularis, limbo elevato, tereti, reflexo. Teste quidem striata est, 

 at stri* microscopic tantnm visibilis." (Muller^) 



The above cursory description has been supplemented by Sterki 

 in his admirable and exhaustive treatment o the genus Vallonia 

 as follows : 



" Moderately umbilicated, more widely for the last half whorl ; 

 convex or depressed conic above; straw colored, transparent, 

 with fine and dense strice which are more regular at the suture and 

 umbilicus ; smooth at the nucleus ; whorls 3-|-4, rather rapidly 

 increasing, v ith a moderately deep suture, the last comparatively 

 large, well rounded, little expanded towards the aperture, not 

 descending in front, or slightly so at the suture. Aperture 

 moderately oblique and inclined, forming five-sixths of a circle; 

 peristome abruptly everted, with a strong white lip, thinner at 

 either end." 



Greater diain. 2*4, lesser 2 ; alt. 1'2 mm. 



Hob. Circumboreal Europe ; Northern and Eastern Asia, as far 

 south as Kashmir; Northern Africa; the Azores and Madeira; 

 greater part of North America. 



" The last whorl is slightly ascending or descending in front, in 

 a good part of the specimens. Sometimes the shell is whitish, 

 inilky-opaque, in living examples ; this seems to be a local varia- 

 tion, as all the specimens in certain places show this peculiarity. 

 The size of the shell varies from 2*1 to 2*7 greater diarn., 2'4 

 being the average. 



" Jaw rather strongly curved, with obtuse ends ; no median 

 projection on the cutting edge, which is denticulated, corresponding 

 to the 10-20 rather sharp, longitudinal ribs, quite irregular in 

 size, course, and distribution, but wanting at the side ends of the 

 jaw. The radula has 65-68 transverse rows of 27 teeth ; of the 

 five laterals the fifth has a small plate and the ectodont double 

 pointed." 



There is nothing to be added to this excellent account. I have 

 refrained from giving the complete bibliography of the species, 

 or the whole synonymy, as this would not serve any useful 

 purpose. 



