REPORT OX THE PTEROPODA. 
121 
Station 246. July 2, 1875 ; Yokohama to Sandwich Islands; lat. 36° 10' N., long. 
178' O' E.; depth, 2050 fathoms; bottom, Globigerina ooze. 
Clio py rami data. 
Station 323. February 28, 1876 ; Falkland Islands to Rio de la Plata ; lat. 35° 39' S., 
long. 50° 47' AY; depth, 1900 fathoms ; bottom, blue mud. 
Clio pyramidata. | Cavolinia infl-exa. 
Station 335. March 16, 1876 ; Tristan da Cunha to Ascension Island; lat. 32° 24' S., 
long. 13° 5' AY; depth, 1425 fathoms ; bottom, Pteropod ooze. 
Limacina injlata. 
Clio ( Styliola ) subula. 
Clio pyramidata. 
Cavolinia trispinosa. 
Cavolinia infiexa. 
Cuvierina columnella. 
B. GEOGRAPHICAL DISTRIBUTION OF THE GENERA. 
AYhen I indicated the geographical divisions (pelagic provinces) which might be 
adopted for the geographical distribution of the Gymnosomatous Pteropoda, 1 I had not 
been entrusted with the Systematic Report on the Thecosomata, which was still in the 
hands of Mr. Alfred E. Craven. Consequently these divisions were based, not on the 
study of all the Pteropoda, but only on the very limited group of the Gymnosomata, 
and therefore in circumstances very unfavourable to generalisation, and apt to lead to 
multiplied subdivisions. 
For the sake of uniformity, however, I have here used the same subdivisions as in 
the case of the Gymnosomata, and it will be seen that they apply tolerably well to the 
Thecosomata also. 
It is to be observed, in the first place, that the Thecosomata are in general more 
cosmopolitan than the Gymnosomata. But it is possible that, after a more complete 
study of the latter, certain forms may be found to be less localised. 
In the Report on the Gymnosomata, the absence of materials made me wonder 
whether there did not exist, for the western part of the southern Atlantic, a special 
pelagic province (the Brazilian). The study of the Thecosomatous Pteropoda has con- 
vinced me that there is none, and that this “ province ” is identical in character with the 
South-west African. It seems advisable therefore to unite it to the latter to form a 
South Atlantic province, in contrast to the North Atlantic one, from which it distinctly 
differs in the presence of some particular species. This South Atlantic province includes 
the region situated to the south of the great equatorial current and to the north of 39° S.; 
and is traversed by the South Atlantic and by the Brazilian currents. In the diagrams 
1 Zool. Chall. Exp., pt. lviii. pp. 61, 62. 
(ZOOL. CHALL. EXP. — PART LXV. — 1887.) 
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