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TERTIARY FAUNA OF FLORIDA 



Adams in February, 1857. It was a heterogeneous group, most of the species 

 ranking with the earher Gomphina of Morch. Three months later Romer 

 proposed, for a group represented by one of Adams' species of Marcia and 

 another referred to Chamelea by Adams, the name of Katelysia. The first to 

 accept this name was Tryon in 1884, who selected V. scalarina Lamarck as 

 type of Romer's group, in which he was followed by Fischer, who changed 

 the name to Catclysia. Chenu, in 1862, and Tryon took as an exemplar of 

 Marcia Adams Venus undulosa Lamarck, which was already the type of Gom- 

 phina Morch, and not available for the later Marcia. Fischer in his " Manuel 

 de Conchyliologie" cited Venus e.valbida Chemnitz (which was included by 

 the Adams brothers in Marcia, though it does not agree with their diagnosis, 

 the surface not being smooth) as the type of Marcia, and it is probably best to 

 accept this rather than make another change on account of the discrepancy 

 alluded to, which may have been due to the worn condition of their specimen. 



In 1864 Romer proposed Hemitapes for a group typified by Venus rimu- 

 laris Lamarck, which he referred to V. virginea Linne, a name appropriated, 

 following Hanky's investigation into the Linnean types, for the Tapes vir- 

 gineus of Europe. But Stoliczka, Tryon, and Fischer by some error cited 

 Venus pinguis of Dillwyn (after Chemnitz), a species of Gomphina, as the 

 type of Hemitapes. The other names cited in the preceding synonymy are of 

 related groups which will find their places in the arrangement hereafter fol- 

 lowing. Several of Cossmann's sections placed with Tapes by Fischer seem 

 more appropriately put with the Venerid forms, as Cossmann originally pro- 

 posed. Of the original Marcia of Adams the group typified by Venus quad- 

 1-angularis Adams and Reeve appears still to need a sectional designation. 



The group as treated here will comprise the Veneridce of subquadrate or 

 trigonal form which occupy the place in the Venerinw that is taken in the 

 MeretricincE by Pitaria and Meretrix, which they much resemble except for 

 the differences of the hinge. The soft parts appear to be unknown, and the 

 group is rather characteristic of the southern hemisphere, especially the Aus- 

 tralasian seas, though a few species reach the tropics of the northern hemi- 

 sphere, where they seem to have been more numerous in Tertiary times. The 

 normal dental formula is ^- i°i°i° -. 



R. oioioi. 



Subgenus Marcia (Adams) Fischer. Type Venus e.valbida (Chemnitz) Dill- 

 wyn. 



Shell large, earthy, with a dull surface sculptured with concentric lamellse 

 and finer concentric striation : there is no radial sculpture : the lunule is large 



