46 THE NAUTILUS. 



ferred to Colambella avara Say, in this journal for May, 1897, as 

 a new species. C. brasiliana (Archiv fiir Naturg., vol. 63, p. 171). 

 The only difference he notes between this and the avara is that the 

 intervals between ribs are smooth, not spirally striated. In the ser- 

 ies of C. avara from Florida examined by me, this supposed distinc- 

 tion proves to be invalid, some of them being quite as smooth as the 

 South American shells. At most, C. brasiliana is only a variety. 

 In the same paper, the Columbella misera Duclos (not Sowb.) is re- 

 named C.japonica. H. A. P. 



NOTES ON URUGUAY AND ARGENTINE FRESH-WATER SHELLS 

 supplemental to the list in NAUTILUS, X, pp. 76-81. 



Amalia gagates Drap. Maldonado, Uruguay. 



Chilina Rushii Pilsbry. The largest specimen collected measures : 

 alt. 22-i, diam. I3i mm.; alt. of aperture 16 mm. 



Limncea columella Say. Maldonado, Uruguay. 



The specimens seem to be the northern species; and if I am right 

 in the identification it is probably a form introduced by man. No 

 similar Limncea is known to me from South America. L. coluim 11 

 occurs as far south as Florida. 



Ancyltis obllquus B. & S., was collected also at San Carlos R., 

 Uruguay. 



The Sphcerium and Pisidium mentioned on p. 80 are as follows : 



Sphceriutn argeutinum d'Orb. Creek in the Prado, Montevideo. 

 Mr. E. R. Sykes of London has, with his accustomed good nature, 

 compared specimens collected by Dr. Rush with the types in B. M. 

 He writes: " There is only one valve of Cyclas ar.gentina, some- 

 what damaged, in the Museum, with which, as far as one can judge 

 from such a wreck, your shell is identical." 



Pisidium Sterkianwn Pilsbry. Same locality. 



Pisidium vile Pilsbry. Same locality. 



Requesting Mr. E. R. Sykes to compare these with Orbigny's 

 type of P. pulchellum, he wrote " These are no specimens of Cyclas 

 pulchella in the Museum and none were presented byd'Orbigny, as 

 you will see by Gray's Catalogue. I am, therefore unable to com- 

 pare these." 



Glabaris latomarginatm Lea and G. tenebricosus Lea were picked 

 up at Buenos Ayres, dead valves only. H. A. P. 



NOTE ON HALISTYLUS. This group was founded by Dall to 

 contain a small, pillar-shaped shell, H. columna, from the east coast 



