11 



Mixed in the same lot with these specimens were a considerable num- 

 ber of G. cronkhitei of all ages and sizes, but even down to the very small 

 ones the present species was fairly easy to separate out by reason of its 

 narrower and steeper walled umbilicus, nearly smooth base, and finely ; 

 rather than coarsely, ribbed upper surface. Shimekii is also lighter in 

 colour and distinctly larger when adult. 



Helicella (Retinella) hammonis (Str^m 1765) 



1765. Helix hammonis Strain, Trond. Selsk. Skr., vol. 3, p. 435, pi. 



6, f. 16 (teste Taylor).. 

 1805. Helix nitidula var. ft Draparnaud, Hist. moll. France, p. 117, pi. 8, 



f. 21-22 (teste Taylor). 

 1830. Helix radiatula Alder, Trans. Nat. Hist. Soc. N. Durh. etc., vol. 1, 



p. 38, No. 30 (teste Taylor). 

 1830. Helix radiatula Alder, Cat. Test. Newcastle upon Tyne, p. 12, 



No. 50 (teste Ball). 



?1830. Helix viridula Menke, Syn. Meth., ed. 2, p. 127 (teste Binney). 

 1841. Helix electrina Gould, Inv. Mass., p. 183, f. 111. 

 1864. Hyalina electrina Morse, Jour. Portl. Soc. Nat. Hist., vol. 1, p. 13, 



text f. 23, pi. 6, f. 24. 



1869. Hyalina viridula Binney and Bland, Land and Freshwater Sh. N. 

 Am., I, p. 34, f. 41-43. 



1884. Hyalina pellucida Lehnert, Sci. Rec., vol. 2, p. 172 (teste Dall). 



1885. Zonites virdulus Binney, Man. Am. Landsh., pp. 23, 27, 28, 32, 



36, 57, 64, 201, 202, 203, 223, 478, f. 21-22. 



1893. Hyalina radiatula Taylor, Nautilus, vol. 7, pi. 86 (recorded from 

 Laggan, Alberta). 



1897. Hyalinia hammonis Westerlund, Syn. Moll. Extram., p. 34 (teste 



Taylor). 



1898. Vitrea hammonis Pilsbry, Nautilus, vol. 11, p. 129. 



1905. Vitrea radiatula Dall, Land and Freshwater Moll. Alaska, pp. 8, 



14,38. 



1906. Vitrea hammonis Walker, Moll. Mich., I, p. 477, f 42 (after Binney). 

 1906. Vitrea hammonis Vanatta, Nautilus, vol. 20, p. 95 (recorded from 



Field, B.C.). 

 1908. Hyalinia radiatula Taylor, Land and Freshwater Moll. Brit. 



Isles, p. 87, text f. 129-134, 145, pi. 2, 4th fig. 



1908. Hyalinia radiatula electrina Taylor, id., p. 97, text f. 139-145. 



1921. Helicella (Retinella) radiatula Gude and Woodward, Proc. Malac. 



Land., vol. 14, pp. 177,185. 



Material Examined 



