454 ALBATROSS PTEROPODS AND HETEROPODS — PECK. 



No shells of ittt'iopods are rectudcd iVoiii tlio drcdiiiu^iis in these 

 waters. Twelve deep-water stations art' also reeorded alon^' the 

 western eoast of Sontli America in the eonrse of the vessel nortliward 

 through 15 dej»rees of latitnde, the depth ranuin.i;' from 100 to 1,1*00 

 fathoms, hut no i)teroi)(»ds are reported. 



No dredging' stations were nuide between oS'^ 08' south and llic 

 equator. lu tact, all the other forty-seven dredging stations in the 

 Paeitie waters, except nine, were nnide in shallow waters ranging from 

 C to about 75 fathoms • in none of these are i)teroi)ods recorded.* 

 But the surface collectious secured them, as is shown in tin' outline 

 ump, between the mainland and the Galapagos Islaiuls, as described 

 heretofore in this article for t]w various genera and species of Carolinid 

 and Clio. No dredging stations are recor«led at exactly these bearings 

 except one at surface 20 in l,.'i70 fatlnmis. 



I have given thns a sketch of the course of the.l//^((/>v>.v.v and theth'pths 

 and, in some cases, the temperature of the waters traversed, in the hoi)e 

 of arriving at some reasons tor the lueeting with pteropods in the dredg- 

 ing i)oints in the >>outh temi)erate /one, upon both eastern, and Mest- 

 ern coasts of the southern i)art of South Anu^rica, in the same measure 

 as they are found in the northern ])arts in the torrid zone. Xot 

 belonging to litoral faunas we should not expect them in the shalloAV 

 dredgings along the coast. ]>nr some other causes must operate to 

 prevent their occurring in the deeper waters of the more open sea 

 along those coasts; and why, therefore, should they not appear from the 

 deeper dredging stations on the western coast of southern South 

 America'? The dredging stations made below latitude oSo were, as 

 has been stated, taken upon the eastern side in shallow waters, Imt 

 upon the western side in much dee])er waters, so that bathybic or 

 zoimry fauna' Avould be very dilferent from that of the shallower seas; 

 the surface temperatures, however, agree very closely. A series of 

 thirteen ccmsecutive stations of the east side below latitnde 38° aver- 

 aged, at surface, 54.3° F. in the hitter half of the nmnth of January; 

 a similar consecutive series of thirteen stations in about the same lati- 

 tude along the Avest side averaged 55° in the tirst half of the month 

 of February. JJut no pteropods are recorded at any surface stations 

 in the Pacific except those indicated upon the outline map in Plate i, 

 while deposit shells were not taken in the Pacific by this expedition. 



Thus it falls out that iderojxxl collections of this voyage are, in 

 origin, for the most part from the Caribean and Pauanniic provinces, — 

 that the two regions furnish material entirely similar in make up — 

 which material belongs almost exclusively to the tamily Cavoliniida', 

 representing all the species except one of the genus Vmwlinia^ the spe- 



*See "table of tiawliug ami dredginjr stations" luatle by JUmtrosa during tlie 

 year and a half ending .Tune 30. 1888,. in the Report of the Work of the U. S. Fish 

 Coiumissiou .Steamer J//»rt/ross from January I, 1887. to .Tune 30, 1888. by Lieut. Com- 

 mander Z. I. Tanjier, U. S. Navy, coinniandiu'v. Fish Commission Rei)ort of 1887." 



