.MANN DIATOMS OF THE A.LBATROSS 70YAGES. 225 



many instances of determining the origin of the materials composing 

 the sea bottom in which they were found. 



The investigations here reported are of value for the purposes jusl 

 mentioned mainly as a means of illustrating the necessity of wider 

 and more thorough work in this line. Nor can these valuable results 

 be secured unless methods particularly adapted to securing diatoms 

 are added to those commonly in vogue i : i sea dredgings and surface 

 gatherings. As both the expenditure of time and the expense inci- 

 dent to combining these researches with those already being carried 

 on would be insignificanl compared with the results to be obtained, 

 it is reasonable to hope thai the necessary measures will be taken. 



In the body of t bis report t here will be Pound many references to t lie 

 service the diatoms are capable of rendering in the determination of 

 sea currents and of the origin of sea bottoms. A few example- may 

 be cited here. In the United States cable surveyfrom California to 

 the Hawaiian Islands and return," a long series of soundings from the 

 stations numbered 2655H to 3202B were found to be very rich in the 

 rat her uncommon quadrate variety of Biddulphia favus I Ehrenb.) Van 

 Ileur. They constitute a practically unbroken series beginning 

 with station 2912H in latitude 155 58' 30" AY., longitude 22 Is' 00" 

 X., running westward to the Hawaiian [slands and on the return 

 voyage eastward ending at about the starting point, namelj at station 

 3018H in latitude 155 57' :;() ,/ W., longitude 21° 56' 00" X. This 

 form, therefore, is as t rulv a local species at t his pari of I lie sea a- any 

 phanerogam is of a terrestrial locality. And this is confirmed by one 

 of II. L. Smith's type slides, No. 599, equally rich in this variety, 

 which he says came from the " Tuscarora soundings south of Sand- 

 wich [slands in 1,468 fathoms,"' a depth duplicated by several of the 

 soundings in the series just referred to. Similarly on the outward 

 voyage at station 291 711 a sounding w as made containing, in addit ion 

 to the quadrate B. favus already mentioned, a number of other 

 diatoms, as Coscinodi.se us nodulifer dan., Navicula aspera Ehrenb., 

 Navicula lyra Ehrenb., Xaricuhi splcndida Greg., Hemidiscus cunei- 

 formis Wallich; and on the return voyage at station 3013H these 

 same diatoms were found. The two stations differ in latitude onl\ 6' 

 30" and in longil ude only 5' 30". This locality is t herefore character- 

 ized by the foregoing combination of species. Boyer 6 speaks of Bid- 

 dulphia robertsiana (Grev.) Boyer as quite rare and coming from 

 Pacific soundings 20 in' 00" N. and 158 1 l' 00" \\\. etc. 1 found it 

 in large quantities a1 21 21' 00" X. and 157 09' 00" W., namely . at sta- 

 tion 2920H. So also Boyer discovered his Biddulphia Jceeleyi on the 

 coast of California; and it is abundant in the soundings of station 



a Townsend, C. II. Dredgings and other records of th< I . S. Fish Commission 

 steamer Albatross, Rep. U. S. Comm. Fish. 1900:387 562. 1901. 

 bProc. A.cad. Phila. 1900: 707. L901. 



