''%ay''] PROCEEDINGS OF THE NATIONAL MUSEUM. 457 



ill this geinis was ]>eii'('<'t]y evident. But hy far the greatest number 

 ol" individuals, and llie largest lelative weight, belonged to the species 

 Umgirostris; of the total D.OOG grams of Cavolinia, 5.513 grams, nearly 

 two-thirds, were from this species. Then come in the order named, 

 nncinata^ fridciitatd, and qKddruhnfata. The material atford(;d by the 

 Lirnacinida' is relati\ely light, and it is i)robable that eveu this esti- 

 mate of these coiled pteropods was somewhat exaggerated by some 

 fragments of si)iral shells (of which only the central sjure remained), 

 which belonged to other spiral gastropods than Limacinida'; although 

 weighed in this connection because they had possibly belonged to char- 

 acteristic species of this group, Limacina was not eveu numerically 

 'abundant. 



The Heteropoda are represented in the ooze only by medium sized 

 A thinta jxyonii, which were quite common. The three principal genera 

 of Khizoi)oda which characterized this deposit were TrilocuUna {?), 

 Ci/clammiiia, and Globujerina, with a few Orbitulina and OrhitouJes (f). 

 These forms could easily be separated from the general mass on ac- 

 count of their large size; but there are (h)ul)tless others that remain 

 mixed with the line debris of the sample, which, if they could be sepa- 

 rated out, Avould add somewhat, but not very materially, to the total 

 weight of the Rhizopoda of the ooze. It is Avorthy of remark that this 

 pteropod oo/e was associated with a giobigei-ina ooze, but so stratitied 

 as to be quite distinct. This api)ears from the account of Capt. Tan- 

 ner,* who describes the trawl as being buried in mud, so as to be 

 landed with difticnlty, when the main nnid bag of the net was lilled 

 with one dei)osit Avliile the smaller ring nets were Jilled with a very 

 different one — the deposits being a flue globigerina ooze, " with only 

 here and there a pteropod shell," and a coarse pteropod ooze, but 

 which was uppermost is not stated; the latter is the one here con- 

 sidered. 



This debris, finally, is that which remained after all was separated 

 that could b<'- readily ichMititicd; it therefore comprises a good deal of 

 very finely ground shells as of some very fine dried silt. But there 

 were also weighed with it otlier forms of life, such as several kinds of 

 gastropods, two kinds of htmellibranchs, and also small sea-urchin 

 shells in considerable numbers — all the material, in fact, that was not 

 quite plainly i)teropod, heteropod, and rhizopod. It is largely made up 

 of triturated shells as the unaided eye may readily determine, which 

 triturated shells, however, represent the scattered remains of Cavolinia, 

 Clio, Cuvierina, Liniaciua, etc., in about the same ratio, I am strongly 

 led to believe, as above given for the rest of the ooze. 



Of course there are many sources of error in such a reduction of this 

 sample of ooze; I have no means of judging what of the smaller con- 

 stituents might not have been taken away in the preparation and 



"Report on the work of the U. S. Fisli Coiuiiiissiou steamer Albatross from Jan- 

 uary 1, 1887, to June 30, 1888, by Lieut. Commander Z. L Tanner, U. S. Navy. 



