134 bulletin: museum of comparative zoology. 



Miocene, and we are enabled to present it for the first time with appro- 

 priate stratigraphic data. 



In addition to the Rudistes of Catadupa already described, this fauna 

 furnishes many new species of Mollusca, all of which are apparently 

 quite distinct from those of the Eocene beds of the North American 

 Coastal Plain. More of the forms, as Cerithium and Lucina and Car- 

 dium, are very large and robust. Of the genera, one at least is new, and 

 still unnamed ; another, Carolia, has not hitherto been found in America. 

 The Catadupa beds also afford specimens of the gastropod genera Conus, 

 Cyprsea, and Thalassa, which have not been found below the Tertiary. 

 There are many indeterminate casts of gasteropods in the Catadupa beds 

 which have a striking resemblance to those of the Cretaceous beds of 

 Jerusalem Mountain. 



De la Beche has frequently noted the occurrence at many localities of 

 the fossils which we now know to belong to the Cambridge beds in the 

 base of his " White Limestone Series," such as the association of Ostrea, 

 Echini, and two large species of Cerithium. In fact, the entire list of 

 species given by him on page 170 of his work most probably came from 

 the Cambridge beds. He figures one of the large species of Cerithium,^ 

 and states that at one time he " considered that it might have been a 

 cast of a shell analogous to C. giganteum ; the latter is, however, a much 

 taller shell than the one under consideration, which in general outline 

 resembles more the C. cornucopice of Sowerby." "^ It is an interesting 

 fact that this fossil also occurs in the Virgin Islands and St. Bartholomew 

 as noted by CI eve. 



According to notes kindly furnished us by Stanton, ** the evidence as 

 to the age of the molluscan fossils from these two localities is conflicting 

 The forms described by Whitfield under the names Caprinula, Capriuella, 

 Caprina, and Radiolites, are all Cretaceous types, and the genera to which 

 they belong are not known to occur elsewhere in more recent formations. 

 On the other hand, all the other fossils that are well enough preserved 

 to be recognizable, have a more modern aspect, none of them being char- 

 acteristic of the Cretaceous. The genus Carolia occurs elsewhere only 

 in the lowest Eocene of Egypt. The large species of Cerithium are of 

 Eocene types, and the same may be said of the Cyproea and several other 

 forms. At any rate, similar species are not known from beds as early as 

 the Cretaceous. If tlie Rudistes and Cliamidpc were absent, there would 

 be nothing to suggest a Pre-Tertiary age for the beds. 



The presence of Rudistes, supposedly Cretaceous genera, in this other- 



1 Op. cit., Plate 21. a Op. cit., pp. 170, 171. 



