-he genus Oardium ic represented 'oy a latge munloer of 

 species and an over-.v^reli:.' .- '-^rity of them are q- ^ e 



t^.oe that immediately? in^i' a warm water habitat; ?''^ the 



smooth or relatively simple forms are identical v/ith, or olcrje- 

 ly related to, reoe eeies that do not occur north of "Florida. 



It is not cm-prising t>r'- memberr:- --f the section Oerastodernia 

 are absent, since the groiip is for the most part confined to temp- 

 erate regions or comparatively deep water^ but, as far as cond- 

 itions of temperature are co-'-cerned, the subg-eniis Papyri de a wo uJ,d 

 be e:cpected to a-^pear in the faunal list, yet it also fails, 

 probably because of some unrecop-nized ee ' ''p-l condition. 



A discussion of the ^ ->•■■-"'-- -...16. be incomr^lc .^ ..i'jhout a refer- 

 ence to the amazing aburidance of a. Trigoniocardia ■; is prod- 

 igality is of added significance when it is consideTed that the 

 -roup is restricte-:! to the .-..-aillean and •;:! - ^,.t. ^ ^ icni areas. 



Although the distribution of the genus Tellina is 

 almost world-v/ide, the grou 1 .ly tropical and 



therefore its e:cteneive development irely another indica- 



tion of the conditions imder which the Bowden fauna flourished. 



Difficulties, both snail en^ • reat, involving various 

 factors are immediately encountered ..;:(iii lui attempt is made to 



■-amiine the bathjmetric conditions from a consideration of 

 '■he ■ abitats of the Recent species included in the fauioa. A 

 rigid aaaerence to the evidence :? -eil b^ the dredging re- 



cords for identical or closely related forms would often lead 



