16 "ALBATROSS" EASTERN TRORICAL PACIFIC EXPEDITION. 



It is impossible at present to indicate the geograpliical distribution of tlie 

 Diatoms, Dinotlagellates, Tintinnids and Radiolarians thus far collected in 

 our pelagic hauls. The same genera of these groups are constantly occurring 

 at very distant points and their distribution seems mainly characterized by 

 the association of varying numbers of specimens of the same genera and 

 species. But undoubtedly a closer tabulation of the species of these groups 

 may lead to a general conception of their geographical distribution over the 

 area of the Pacific explored by the "Albatross." 



The principal genera of Diatoms met with are Coscinodiscus, Asteromphalus, 

 Planktoniella, Rhizosolenia, Synedra, Gossleriella, Eucampia, Thalassiotlirix, 

 Biddulphia, Euodia. 



Of the Tintinnids: Tintinnus, Undella, Dictyocysta, Amphorella, Cytta- 

 rocylis, Codonella, Poroeca are the principal genera found. 



Coccoliths, Coccospheres, and Rhadospheres, occurred in the whole area 

 explored by the " Albatross." Noctiluca and Pyrocystis were not uncommon. 

 Challongeridae, Challengeron, Tuscaroridae and Tuscarusa were obtained in 

 nets sent down to 150 and 300 fathoms, and from the surface. Trichodes- 

 inium, Ilalosphfera, and other pelagic Algae were most common. 



Among the Radiolarians the following genera have been noted, many 

 of which have been described as living at great depths while in reality they 

 are only the dead carcasses of types living at the surface or close to it and 

 gradually falling to the bottom : 



Collozoum Rhopalastrura Cyrtophormis 



Belonozoum Conchidium Lithostrobus 



Cenosph;«ra Litholophus Lithomitra 



Ethmosphifra Acanthonia Eucyrtidium 



Odontospluera Acanthostaiirus Lithocampe 



Chci-nieosphau'a j'Speciesdescribedby Beloiiostaurus Aulactinium 



o- 1 1 Ilaetkd as found in r, , a i ^i 



Siphonosplirera ■|25(iofati.on.8inCen- /jgostaurus Aulocantlia 



1'r3panosph;era I'"'"' l^a'^'A';- Amphibelone Sagosphasra 



Soleiiospliuira I'erispyris Aulospha'va 



Hexastylus Neplirospyris Cannospha>ra 



Hexacontium Litharaclinium Challengeron 



Eeliinomma Carpocanistvuni Challengeria 



Croniyomma Cornutella Cadiuni 



Pityomina Tripocyitis Mediisetta 



Ellipsostylus Lyelinocanium Euphy.setta 



Stylatractus Carpocaniuni Circopovus 



Spongocore Sethoconus Tuscarora 



Poroiliscus Dictyoceras Tnscarusa 



Euehitonia Theoealyptra Tu.scaridium 



