42 TIIK NAUTILUS. 



polished beneath ; color yellow, yellowish-green or light brown. 

 Whorls six to eight, narrow, slowly widening, the last a trifle descend- 

 ing in front. Aperture subtriangular, oblique ; peristome blunt, 

 not expanded, thickened within, with or without lip teeth ; parietal 

 wall bearing a stout, triangular, erect entering tooth. 



The species may stand as follows : 



(1.) No lip-teeth ; body-whorl with several internal ])airs of 

 denticles visible through the base. H. pohjgyrella. 



(2.) Peristome with two lip-teeth ; no denticles inside the body- 

 whorl. H. Harfordiana. 



Dr. Cooper's ingenious supposition that the internal denticles 

 of H. polygyrella are " swallowed" lip teeth I find to be erroneous, 

 as they are formed quite a distance within the whorl, not at the 

 edge of the advancing lip. 



H. Harfordiana has been found only at the spot named above, 

 and only two specimens are known ; that figured on the plate ac- 

 companying this paper, and one other, a young shell, in the collec- 

 tion of Dr. Cooper. The earlier whorls are broken in the type spec- 

 imen. 



ON SOME MARINE MOLLITSKS FROM THE SOUTHERN COAST 

 OF BRAZIL. 



BY DR. M'. H. BALL. 



In the preliminary report on the mollusca obtained on the voyage 

 of the Albatross around Cape Horn (Proc. U. S. Nat. Mus. XII, 

 No. 773, pp. 219-362, 1889) I enumerated a number of Antillean 

 mollusks which were found to extend their range from the coast of 

 the United States to the eastern shores of Brazil, to the Abrolhos 

 Islands and even further south. Subsequently a few others, also 

 from the Albatross collection, were noted as extending to Brazil, in 

 Bull. 37, U. S. Nat. Museum. Since then I have received from Dr. 

 H. von Ihering, of Porto Allegre, a small collection of very poor, 

 beach-worn material, largely in fragments, but still identifiable, 

 which still further enlarges the range of some of the species, and 

 adds to the list of species some of the common forms of the United 

 States coast which had not before been suspected to reach such 

 southern latitudes. It is probably that the great volume of fresh 



