15 



Material Examined 



The present determination of these specimens has kindly been confirmed 

 by Dr. G. Dallas Hanna of the California Academy of Sciences, who writes 

 (in litt., November 2, 1920), "I consider your identifications correct in 

 every case. The specimens have been compared with material from Eng- 

 land, Norway, Maine, Alaska, and Pleistocene fossils from Kansas and 

 Iowa. Those from the Tobacco plains locality approach the Alaska forms, 

 which I consider a new species, but they are not quite mature and there- 

 fore not entirely comparable. The Alaska specimens are heavier and more 

 obese, as shown by the following measurements:" 



All the present specimens have been recorded by Whiteaves (1905, 

 p. 171) as Sphyradium edentulum (Draparnaud). 



Punctum pygimeum (Draparnaud 1801) 



1801. Helix pygmcea Draparnaud, Tabl. Moll., p. 93 (teste Taylor). 

 1805. Helix pygmcea Draparnaud, Hist. Moll., p. 114, pi. 8, f. 8-10 



(teste Dall). 



1841. Helix minutissima Lea, Proc. Am. Philos. Soc., vol. 2, p. 82. 

 1844. Helix minutissima Lea, Trans. Am. Philos. Soc., vol. 9, p. 17. 

 1864. Punctum minutissimum Morse, Jour. Portl. Soc. Nat. Hist., vol. 1, 



p. 27, text f. 69-70, pi. 8, f. 71. 

 1885. Microphysa pygmcea Binney, Man. Am. Landsh., pp. 57, 71, 482, f. 



31-33. 

 1898. Punctum pygmceum Pilsbry, Nautilus, vol. 11, p. 142 (merely 



catalogued). 

 1905. Punctum pygmceum Dall, Land and Freshwater Moll. Alaska, 



pp. 9, 53. 

 1909. Punctum pygmceum Taylor, Mon. Land and Freshwater Moll. 



Brit. Isles, p. 157, f. 215-219 (European form). 



1909. Punctum pygmceum minutissimum Taylor, id., p. 161, f. 220-223 

 (American form). 



