456 ALBATKUSS PTEKOPODa AND 111:'JM:K()P()DS — PECK. 



waters above, aiul, iftlie ji,roator i)ait oi" the oo/.e is made up of Cavo- 

 liniidie deposited thi()iii;li eoiistaiit and suecessive seasons in the same 

 region, its comi)Osltion must bear some relation not only to tlie pelagic 

 but also to the zonary and bathybie launie by \vhieh it is laid down in 

 this region. 



This "pteropod oo/e" in question Avas dredged in 1,019 fathoms depth, 

 and when dried it proved to be a mass made njt almost entirely of 

 pteropod shells in various states of entirety, in which condition it was 

 submitted for study. In order to compare the genera and species, as 

 shown by deposit, Avith those of the same genei'a and species taken 

 alive at the surface, the specimen of <toze reported was separated into 

 its component parts and weighed. A comparison by weight, of course, 

 ex])resses (mly the amount of material contributed to the general mass 

 of the dejjosit by each grou]), au<l bears no exact relation to the num- 

 ber of individuals in each of the various groups, because of the great 

 dili'erence in individual size; one of the largest, (\ tri(lcnf((t<( for in- 

 stance, will outweigh many of the small Clio siihiddta', one large Clio 

 halantium will contain more material than several of the much smaller 

 Clio pyrdniidata, and yet a table of com])arative werghts shows very 

 clearly, 1 think, tiie relative activity of the scHirces from which these 

 great deposits are laid down, both as regards individual numbers as 

 well as the mass of material contributed by each kiiul. Such a table 

 of relative weight of the i)rincipal constituents in their order runs 

 thus : 



(iianis. 



Carolinia Jo)igiros1ri>i, Iridotiata, uncinnta, qiiadriiloilaia 0.177 



Cavolinhi injiixa 084 



Carolinia Irispiiiosa 500 



Cii ritri)ia coIutneUa 808 



Clio (s. sir.) pyramidata 861 



Clio {StiiUola) subitlata 276 



Total Cavoliniidii- 9. 006 



Limaciiiida- (tVagmeiits) 151 



Limacitui injiata 006 



Total Limac•illicl;l^ 157 



Atlanta peronii ? 116 



Total Heteropoda 116 



Cychimmiiia 170 



Triloculina (?) 282 



Glohigerina (etc.) 082 



Total Rliizopoda 5'M 



D<''bris 7. 808 



Total oilze 17. 651 



The si)ecies under the genus Carolinia were weigiu'd together, be- 

 cause the specific place of so many of the fragments of shells ccmld not 

 be distinguished owing to their fragmentary state, although their place 



