TERTIARY FAUNA OF FLORIDA. 



Superfamily VENERACEA (Continued). 



Family VENERID^. 



THE most beautiful, genetically the most highly developed, and one of the 

 most prolific in the recent faunas, this family has had a varied history 

 and complicated elucidation. 



The Linnean genus Venus was naturally heterogeneous, comprising animals 

 now scattered in several distinct families. If the whole subject were to be 

 revised here for the first time, there is no doubt the best course would be to 

 adopt as the type of the genus Linne's first species, Venus dione, not only be- 

 cause it stands first, and was cited as an example in the " Fundamenta Testa- 

 ceologica" by Linne himself and by Cuvier in his " Tableau" of 1798, but also 

 because it was the species selected by Linne upon which he based the technical 

 terms used in the description of the group, and it was widely known collo- 

 quially among collectors and naturalists as " the true Venus shell," and by 

 similar appellations indicating that it was generally considered in the eighteenth 

 century as the particular exemplar of the group. In view of the fact that 

 Lamarck selected another form in his " Prodromus," which has been generally 

 accepted as a type for the restricted genus, it would be unwise to attempt to 

 reverse the course of history. 



The first work in which any revision of the Linnean genus was attempted 

 is that of Scopoli in 1777, who, following Adanson, segregated Dosinia and 

 Codakia, but otherwise contents himself by pointing out that the group typified 

 by Venus meretrix Linne has a hinge which does not fit the Linnean diagnosis 

 of the genus. 



A year earlier Da Costa, who at that time had not accepted the Linnean 

 system of nomenclature, proposed for a group practically synonymous with 

 Venus the name Pectunculus, including under this designation species of 

 Cyprina, Chione, Dosinia, and Arcopagia, as appears in his " British Con* 

 chology" of 1778, in which he at last uses a consistently binomial nomenclature. 

 In the anonymous " Museum Calonnianum," edited by Da Costa from a manu- 



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