TRANSACTIONS OF WAGNER 

 1460 



TERTIARY FAUNA OF FLORIDA 



y^Euglesa Leach, Syn. Moll. Gt. Brit., p. 291, 1852; Clessin, Malak. Blatt., xviii., p. 189, 



1871, Pisidiiim pusillum Gmelin : Westerlund, Fauna Paljearct. reg.. vii., p. 36, 1890. 

 '^Cycladina Clessin, Mai. Blatt., xviii., p. 189, 1871, Pisidium pusillum Gmelin, P. ob- 



tusale Pfr., and P. nitidwn Jenyns. 

 "^Fluminina Clessin, in Westerlund, Fauna Moll. Suecica, p. 532, 1873, Pisidium am- 



nicum Miiller; Westerlund, Fauna Palsearct. reg., vii., p. 18, 1890. 

 '^Rivulina Clessin, in Westerlund, Fauna Moll. Suecica, p. 532, 1873, Pisidium globulare 



Clessin ; Westerlund, Fauna Palaearct. reg., vii., p. 20, 1890. 

 "^Fossarina Clessin, in Westerlund, Fauna Moll. Suecica, p. 532, 1873, Pisidium Henslow- 



ianum Shep. ; Westerlund, Fauna Palaearct. reg., vii., p. 22, 1890 ; not Fossarina 



Adams, 1863. 

 Gallileja Westerlund, Fauna Palaarct. reg., vii., p. 18, 1890, in synonymy, err. typ. pro 



Galileja O. G. Costa. 

 Cyclas (sp.) Blainville, Diet. Sci. Nat., xxxii., p. 33, 1824; Man. de Mai., i., p. 551, 1825. 



The nomenclature of this group has been treated carelessly by authors, the 

 result of which is, unfortunately, that the generic name now in common use 

 will have to be discarded for a prior one ; in fact, there are two prior ones 

 which have been passed over in defiance or neglect of the rules of nomen- 

 clature. 



In 1818 Ferussac divided the heterogeneous group which had been called 

 the Cyclades into two subgenera, the first of which was Corneocyclas. He 

 named no type, and his list of species contained five species of Sphcerium, two 

 species of Cyrena, and three of Pisidium. Spharium and Cyrena, being prior, 

 cannot receive the new name, which must therefore be reserved for the Pisidia. 

 Of these there are the following species: fontinalis Drap. ^ pusilla Gmelin, 

 dubia Say ^ virginka Gmelin, and amnica Miiller. Of these virginica was 

 named Phymesoda by Rafinesque in 1820; amnica was called Pisidium by C. 

 Pfeiffer in 1821 ; leaving unappropriated piisilla, which must be taken as the 

 type of the restricted genus Corneocyclas. All belong to one genus but may 

 be available for the subdivisions into which that genus may be divided. Now 

 P. amnicum Miiller has usually been taken as the type of the genus Pisidium 

 because it is the first of the three species cited in connection with the first 

 description of the genus. But PfeiiTer gives in his diagnosis the specification 

 that his genus has " an der rechten Schale ein, an der linken Schale zwei" 

 cardinal teeth, therefore out of the three species he cites it is advisable, if one 

 can be found, to take one which wholly agrees with his diagnosis, and P. am- 

 nicum has two teeth in each valve. It seems that the other two species do have 

 the required character, therefore one of them should be utilized as type. Since 

 P. obtusale is intimately related to P. pusillum, so that they will go in one 



