

TRANSACTIONS OF WAGNER 

 666 



TERTIARY FAUNA OF FLORIDA 



a dissertation for the latter to defend on his examination for a degree, is 

 responsible for the confusion which has led to the ascription of this genus 

 and others contained in the same paper to Philippson, for whom the disserta- 

 tion was written, as well understood by the earlier writers. 



It is less clear why the acceptance of the genus (which even Linnaeus 

 had it in mind to adopt in his proposed thirteenth edition of the Systema 

 Naturae) should have been made under a wrong name, and a name already 

 proposed for a different group by Retzius himself. In preparing the list of 

 families (p. 483 antea) the name Pcrna was incautiously accepted from Fischer 

 without investigation. The latter, while admitting it to be " well characterized 

 and prior to Perna Lam.," objects that Retzius's first species cited is an Avicnla 

 (A. scitiianrita L.). It is enough that the name Perna was already in use and 

 not available for Lamarck to use again ; but, apart from this, Chemnitz, the 

 chief iconographer of that time, had figured a Mclina under the name of 

 Ostrea scinianrita Linnanis, whence Retzius doubtless derived it ; Linnajus him- 

 self, in his manuscript notes on Ostrea scinianrita for the proposed thirteenth 

 edition of the Systema, states that its hinge was like that of Ostrea pcrna, of 

 which Solander thought it only a variety, and authors since have differed as 

 to the generic place of the species. If every genus in which a single species 

 not belonging to it was included by the originator is to be rejected, only 

 monotypical genera will remain. There is no warrant for the assumption that 

 the first species is necessarily the type, and if it is found to differ from the 

 generic diagnosis while others in the list agree with the generic characters 

 given in the diagnosis, that is sufficient to exclude the divergent species from 

 the position of type. As a matter of fact, it appears clearly from Retxius's 

 paper that no type was selected, though 0. pcrna L. may be inferred, and 

 Ostrea ephippinin was recognized and this species fixed as type by Schumacher 

 and all subsequent revisers until the advent of Fischer's Manual. 



The synonymy might be much extended, but that given contains the 

 essential citations. 



Subsequent writers have fixed two sections or subgenera under Melina : 



I. Isoguomon (Bolten) Link. 



Shell plain, ventrally produced, with a posterior wing. Type Ostrea 

 isognoinon Gmelin. 



The name Isogonum appears to have been a misprint, as the word is 

 spelled in several different ways in the Museum Boltenianum. 



