Section Anomalocardia Schumacher. Type Venus ftexuosa Linne. 

 Surface with predominantly concentric sculpture, vernicose periostracum, 

 and the adjacent surfaces of the posterior left cardinal and right nymph mi- 

 nutely rugose. Distribution American and west African. 



Section Anomalo discus Dall. Type Cytherea squamosa Lamarck. 

 Surface with reticulate sculpture, the radials and concentric ridges subequal, 

 a dull, papery periostracum, and the hinge without rugosities. Distribution, 

 Indo-Chinese. 



Anomalocardia floridana Conrad. 



PLATE 55, FIGURES 14, 15. 



Venus fioridana Conrad, Am. Journ. Science, 2d Ser., ii., p. 400 (figure), 1846. 

 Venus penita (pars) Heilprin, Trans. Wagner Inst, i., p. 116, 1887. 



Oligocene of the silex beds at Ballast Point, Tampa Bay, of the Sopchoppy 

 limestone, and Bailey's Mill Creek sink, and of the Tampa limestone overlying 

 the silex beds at Ballast Point, Florida. 



This species is one of the most characteristic of those found in the silex 

 beds, and as Conrad figured only a young, not very characteristic, specimen, 

 and Heilprin did not figure it at all, it was thought best to give illustrations 

 of it. 



Conrad figures two species, the first and largest under the name of Venus 

 penita (page 399) and the second V. floridana. I am somewhat inclined to 

 think Heilprin was right in uniting them, but in a very large number of speci- 

 mens I have found none which agrees precisely with Conrad's figure of V. 

 penita. The identity of the common species of the silex beds with V. floridana 

 is, however, undoubted, and therefore I have preferred to use that name, as 

 Conrad's type of V. penita did not come from the silex beds, but was a cast 

 in limestone, evidently the Tampa limestone, the next succeeding horizon. 

 There is a chance that V. penita may turn up again and prove distinct from 

 V. floridana, and it seems more prudent for the present to treat them sepa- 

 rately. 



The species is quite variable in form, as the following measurements will 

 show: 



Average adult height 31.0, length 38.0, diameter 20.0 mm. 



Elongated adult " 25.0, " 36.0, " 20.0 mm. 



Elongated young shell " 20.5, " 28.0, 15.0 mm. 



Short young shell " IQ-O, " 23.0, 15.0 mm. 



