1685.2 PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 273 

 .^.^.^^===^ . ^=-.^^ ■ JLAf^ ^^^^^^^ 



VoS. ¥SII, I^o. 18. Washliag-toBB, 1!>. €. JibIv f-B^ 1885. 



^ ' ,^'- . 



aUms, wliile the shell itself is well distinguished. The front view, while 

 accurate for some individuals, has the aperture much too flat, and not 

 nearly as round as iu most specimens of this species. 



PI::iiorbis dilatatus (jJould. 



riaiiorJ/is (UlaUtliifi GUI. (1841), Biniiey, 1. c, p. 131. 



Iluhital. — New Ei'gland to Maryland, Binney; iSaint Augustine, 

 Fi.i., i!ein})Lill: ditch at Gainesville, and brook near EnteriDrise, Lake 

 Monroe, Dall. 



This seems to be the commoner small si>ecies in Florida. I have some- 

 thing almost exactly similar from jSTorthcrn Mexico. 



Planorbis trivolvis Say. 



rianorbis irivolvis Say (1817), Biuiiey, 1. c, p. 11.5. 

 Not quoted by Binney from Florida. Poey's identification of a 

 ^Juban species with it is denied hy Arango, who considers it as not 

 belonging to the Cuban fauna. The Florida specimens are not large, 

 but it seems widely spread, and is one of the species common to the 

 sinks or natural wells of the interior. Palatka, Johnson's Sink, Alachua 

 County, brook at Enterprise, Dall ; marsh near Furguson's Pass, Hemp- 

 hill. Abundant and variable. 



Ameria scalaris Jay. 



Paludina scalaris Jay, Cat SIi., 3d ed., p. 112,1)1. 1, tigs. 8,9, 1839. 

 Fliifsa scalaris Haldemau, Mou., p. IU, pi. iv, f. 9, 1842. 

 Ameria scalaris Dall, Ann. Lye. Nat. Hist. N. Y., p. 35'), 1870. 



Habifat. — Tampa Bay, Anthony; Everglades, Florida, Jay; Lake 

 Eustis, Florida, Wetherby ; Saint John's Eiver at Satsuma, brook at 

 Enterprise, Lake Monroe, Dall. Also iu the marl of which the shell 

 r,K)U!!ds are built. 



This remarkable form, of which the largest number of relatives are 

 found in thi3 southern hemisphere, does not belong to the Fhysidce, but 

 to the Limnieidm. The soft parts resemble those of Planorbis, according 

 to Wetherby. It appears to be abundant £g; the proper season, which 

 is, however, later than most vi-sitors remain in Florida. It is common 

 in the shell marl of the Indian mounds, and attains a considerable size 

 (15'"") and great solidity. Not all the species are carinated, and some 

 of them much resemble a Physa in general outline, though wanting the 

 polished surface of that genus. 



Family Ancylid^. 



Ancylus obscurus Haldemau. 



Anpijlus ohscnriis Ilald., Mou., p. 9, pi. 1, f, 4, 18i4. 



Habitat. — Xolachucky Eiver, Haldeman ; ditch at Gainesville, Fla., 

 brook at Enterprise, Lake Monroe, Dall; marsh near Furguson's Pass, 

 Proc. Nat. Mus. 85 18 



