Bulletin 30 



modern representatives of others are Pacific, living on the 

 West Coast of the Americas, or more rarely are found in the 

 Indian Ocean. Sowerby* was struck by this on examining Hene- 

 ken's collection in 1849. 



Resemblance to the recent. — At first glance the fossils seem so 

 like the recent that one would not attribute to them their real 

 antiquity. But actual comparisons show that in the great major- 

 ity of cases the fossils are not absolutely the same but are ances- 

 tral, being the stock from which the recent has evolved. Yet in 

 a few instances they have lived on without apparent change agree- 

 ing perfectly with recent specimens collected by our party on the 

 Monte Cristi beach where several hundred recent species were 

 gathered. 



More exact study of the Bowden and Santo Domingo faunas 

 has much reduced the proportion of the recent. Gabbf gave for 

 his Santo Domingo collection 217 extinct species and 97 recent 

 forms, while of the 451 species discussed by the writer in Part 1 

 of this memoir only 34 are regarded as identical with the recent, 

 and some of these are considered doubtful. 



Deep Sea Affinities. — Our faunas as a whole are made up of 

 molluscan genera inhabiting warm seas at moderate or shallow 

 depths, many being dwellers on coral reefs. And Dr. Cushman 

 who has most kindly studied our collections of Foraminifera in- 

 forms me that no characteristic deep sea genera are present al- 

 though certain ones may also be found at some depth. The gen- 

 eral character is against deep water conditions especially the 

 abundance of Orbitolites and Amphistegina which are typical of 

 shallow water. The same is indicated by our hermit crabs from 

 Bluff 3. 



Nevertheless a few forms have their nearest allies in deep 

 water. For example Noetia {Sheldonella) maoica recalls certain 

 deep water Bathyarcas and Cucullarias. The probable descen- 

 dant of Crepitacella cepula is C. Gabbi found in nearly freezing 



" :; "0uart. Jour. Geol. Soc. London, vol. 6, 1850. 

 fTrans. Amer. Phil. Soc. vol. 15, p. 101, 1873. 



