/6 THE NAUTILUS. 



evanescent in the outer teeth. The radula is 0'">5 mill, long, 0'14 

 wide, and so one tooth measures about 0'0045XO'0035 mill. 



This is so radical a difference from the Pupida? that our species can 

 no longer be placed under that family. It comes nearest Pimctum 

 jtygmceum Drap., 1 the radula being of the same type, and also the 

 jaw is of the same formation, being quite low and composed of dis- 

 tinct plates. 



As to the generic name, Sphyradium Charp. 1837(=Columella 

 West., Edentulina Cless., both 1876, teste Westerlund) must be 

 used. 



An interesting analogue is "Pupa" neozelanica Pfr., with much 

 the same form of shell, which Mr. H. Suter, a few years ago, has 

 shown to be no Pupa, but a Charopa. 



It may be added that the American form is absolutely identical 

 with the palsearctic, even showing the same wide range of variation. 

 There is no need, then, to name it Sph. "edentulum simplex." Just 

 so, to mention it by the way, Punetum pi/gmcfum Drap. is identical 

 on both continents, and so it is equally useless to name it P. ]>;/yina:i/m 

 minutissimum. 



LIST, WITH NOTES, OF LAND AND FRESH WATER SHELLS COLLECTED 

 BY DR. WM. H. RUSH IN URUGUAY AND ARGENTINA. 



BY HENRY A. PILSBRY AND WILLIAM H. RUSH. 



In presenting this list of land and fresh water shells from Uru- 

 guay and Argentina, perhaps it will be well to state precisely the 

 localities at which collections were made, especially so from the 

 Uruguay River, which region seems to have been omitted from the 

 report of D'Orbigny. The U. S. S. Yantic, to which the writer 

 was attached, arrived at Montevideo, Uruguay, in January, 1892. 

 The public park, El Prado, of the city proved to be the richest re- 

 gion near by ; the suburbs of the town were rich in Hi-lix lucd-n, as, 

 indeed, were many places in Uruguay and Argentina; several large 

 tracts are preserved for the cultivation of them for the supply of the 

 Italian markets. The Cerro, which is quite a prominent hill on a 



1 In the radula of one specimen of P. ;/;/;/<. < inn r+17 teeth were counted in 

 a transverse row, r-f-16 in another, and SO I 78 ) rows were found. The laterals, 

 except the last one or few, were bicuspid. (t'onf. E. S. Morse, Pulmonifera 

 of Maine, p. 27, pi. 8, fig. 71.). 



