10 THE NAUTILUS. 



collected by tlie University of Michigan expedition in 1905, and are 

 very uniform in the peculiar features above described. P. hicarinatus 

 was collected in 1904 and 1905 in a number of different localities in 

 various parts of the island, but all such were quite typical in form. 



The longitudinal sculpture of this form is unusually strong for the 

 species, and reminds one ot the heavy sculpture of P. corpulentus 

 Say, but differs in being less regular and lacking the acute ridges of 

 that species. Royalensis is nearer to portagensis than to any other 

 form of hicarinatus, but differs in being wider and in the develop- 

 ment and position of the superior carina, wider umbilicus, stronger 

 basal carina and shape of the aperture. 



(To be continued.) 



BECEITT FBESH-WATEB FOSSILS FBOM BBONX BOBOUGH, 

 NEW YOBK CITY. 



BY EDWIN W. HUMPHREYS. 



The shells here mentioned were found at what is now 171 St. and 

 Morris Ave., Borough of the Bronx, New York City. The swamp 

 which is situated at this point lies in a long, narrow, anticlinal valley 

 which has been eroded in the Inwood Limestone. "When the street, 

 now known as Morris Ave., was filled in across the swamp, the peaty 

 deposit, which had accumulated here, was forced up to heights 

 of several feet on either side of it. This caused the peat to crack in 

 all directions and revealed numerous pockets which were full of small 

 shells. The shells were extremely abundant ; so thickly were they 

 heaped together that they could easily be scooped up with a garden 

 trowel. From the manner in which they were found it would seem 

 as if they had been gathered together by currents or eddies in the 

 waters of the swamp. All of the shells were bleached to a chalky 

 whiteness and were very fragile. The following species were found. 



Amnicola Umosa (Say) Hald. Shells of this species, though com- 

 mon, were not very abundant and were usually more or less injured. 



Valvata tricarinata Say. These were exceedingly numerous, hun- 

 dreds of them being heaped together in a single pocket. They were of 

 all sizes, some being so small that they were lodged in the apertures 

 of the larger ones. Evidently they represented individuals of all ages. 



Physa heterostropha Say. This species was rather scarce. 



Planorbis hicarinatus Say. This form was also uncommon. 



