290 PROCEEDINGS OF THE ACADEMY OF [1897. 



NEW SPECIES OF MOLLUSKS FROM URUGUAY. 

 BY HENRY A. PILSBRY. 



The following descriptions are based upon material collected in 

 Uruguay by Dr. Win. H. Rush, U. S. N. The marine shells were 

 obtained at Maldonado Bay by dredging in from 3 to 6 fathoms 

 depth. A list of all the species collected may be found in the 

 " Nautilus" for May of this year, p. 6. 



Few coasts of like extent have been so little explored conchologi- 

 cally as the eastern shores of South America from Guiana to Cape 

 Horn. The limits to the southward of the Antillean mollusk fauna 

 are only of late becoming known, largely through the collections 

 made by Dr. von Ihering and others, and recorded by Dall, 1 al- 

 though the collections made at Rio Janeiro and Bahia by the 

 Wilkes Exploring Expedition, 12 and by the commission of natural- 

 ists 3 sent by the Spanish Government, have been of value in this 

 enquiry. Mr. E. A. Smith's catalogue of the mollusks of Fernando 

 Noronha, 4 and numerous records in the volumes on mollusca of the 

 Challenger Reports, further swell the list. 5 It would seem that the 

 fauna, as far south at least as the southern limit of Brazil, is prepon- 

 derantly Antillean, but with a certain number of special forms not 

 represented in the West Indies, some of them, like Strombus Goliath, 6 

 notable for their size or peculiarity. To the southward of Brazil, 

 the special or non-Antillean forms seem to predominate over the 

 Antillean, although there is of course a very gradual overlapping, 

 as would be expected from the lack of any salient coastal feature 



1 Nautilus, V, pp. 26, 42 ; VI, p. 109 ; X, p. 121. Also Proc. XJ. S. Nat. 

 Mus., XII, p. 773, pp. 219-362. 



2 Mollusca and Shells, by A. A. Gould. 



3 J. G» Hidalgo. Moluscos del Viaje al Pacifico, part 3. marine univalves. 



* Journ. Linn. Soc. Lond., Zool. XX. Consult also Smith's paper on the 

 mollusca of St. Helena and Ascension, P. Z. S., 1890, where many Antillean 

 species are recorded. 



5 There are some brief lists of merit other than those above mentioned as 

 well as many records for single species from this region, scattered through 

 the general literature of conchology. 



6 This magnificent Stromb occurs on the coast of Brazil. The writer 

 saw numerous examples in the Brazilian Fisheries Exhibit at the Columbian 

 Exposition in Chicago in 1893. 



