TRANSACTIONS OF WAGNER 

 1346 



TERTIARY FAUNA OF FLORIDA 



According to Zittel both subdivisions of Codakia in European horizons 

 recede to Miocene time, but in the New World they certainly appear as early 

 as the Middle Oligocene. One species, which Mr. T. H. Aldrich identifies with 

 Conrad's unfigured Lucina peiievis of the Vicksburgian (and, if so, most un- 

 happily named), occurs at Red Bluff and Carson's Creek, Mississippi, as well 

 as at Vicksburg, and, while not a characteristic Jagonia, would undoubtedly 

 be best placed in that group, having well-developed radial as well as concentric 

 sculpture. It must be borne in mind in considering my references of Eocene 

 forms that few of them have attained the full development of the groups to 

 which I have referred them when the latter are best developed in or typified 

 by species of later horizons. They do, however, constitute what Agassiz used 

 to call synthetic types, and often seem, as one might expect, nearly intermediate 

 between groups which in the Miocene or Pliocene have become well differ- 

 entiated. In such cases I have used my best judgment as to the preponderance 

 of characters, while recognizing that a different opinion might easily find some 

 facts to support it. 



In the white Oligocene limestone of Clairmont, St. Ann's, Jamaica, which 

 is regarded by Hill as somewhat older than the Bowden horizon, a well-de- 

 veloped species of Codakia occurs, of which fragments insufficient for descrip- 

 tion are in the National Museum. So far as sculpture and general form are 

 concerned it can hardly be discriminated from the recent C. orbicularis. It 

 may very likely be this species which Guppy has listed under the name of 

 Lucina tigrina from the " Miocene" of Jamaica. I have not seen any species 

 in the Bowden marl which closely simulated C. orhicularis, though analogues 

 of several recent forms (which have been referred to under names given to 

 recent species) occur, as will be shown later. 



Codakia spinuloea n. sp. 

 Plate 52, Figure 19. 



Oligocene of the Bowden marl, Jamaica, West Indies. 



Shell nearly orbicular, moderately and regularly convex, solid, with pointed, 

 low, prosogyrate beaks ; lunule small, deep, cordiform ; sculpture of small, 

 low, flatfish, indistinct radials with slightly excavated, narrower interspaces ; 

 these are crossed by indistinct concentric threads, incremental lines, and occa- 

 sional ridges due to resting stages ; at what would be the intersections, if the 

 concentric sculpture were better developed, the shell shows small, squarish 

 nodulations which towards the ends and dorsal margins become minutely 

 spinulose ; the right valve has the hinge well developed, the anterior lateral 



