122 
THE VOYAGE OF H.M.S. CH ALLEN GEE . 
of geographical distribution the name South-west African province will therefore be 
replaced by that of South Atlantic. 
Genera of Thecosomata have been observed in all the warm and temperate seas, that 
is to say, in eight out of ten pelagic provinces. In the case of several of these provinces 
the first mention of certain genera is due to the results of the Challenger Expedition ; for 
example in the case of the South Atlantic, Australasian, North Pacific, and South-east Pacifi c. 
The . maximum geographical extension is found in the genus Limacina, as compre- 
hended in this Report. In fact Limacina is not absent from any of the ten provinces 
which have been adopted in the Systematic Report on the Gymnosomata. 
Peraclis is more local ; at least it has not hitherto been observed except in the 
North Atlantic (including the Mediterranean), West Pacific, and South-east Pacific 
provinces. But it seems to me probable that it will afterwards be found in the other- 
warm seas, at least in the South Atlantic, Indian Ocean, and Australasian provinces. 
(Empty shells of Peraclis reticulata and Peraclis bispinosa have already been got in 
sediments from the bottom of the sea, at lat. 9° 5' S., Station 122.) 
In the group of Cavoliniidse the genera and even the subgeneric sections are almost 
all cosmopolitan, not being absent even in the cold provinces (Arctic and Antarctic). 
Thus forms of Clio belonging to the subgenera Creseis, Hyalocylix, and Styliola have 
been found in all the eight warm and temperate provinces. 
The subgenus Clio, s. str., although with a geographical distribution not quite so 
extensive as the genus Limacina, has been found in the eight warm and temperate, 
and in the two Arctic ( Clio pyramidata) and Antarctic provinces ( Clio australis and 
Clio sulcata ). 
Lastly, the geographical distribution of the genera Cavolinia and Cuvierina also 
extends throughout the eight warm and temperate provinces. 
Leaving the calcareous -shelled Thecosomata, and passing to the Cymbuliidse, we 
find that like Peraclis and the different genera of the Gymnosomata they have as yet 
been insufficiently studied. The presence of the genus Cymbulia has been proved in 
the following provinces — the North Atlantic, Indian Ocean, and Australasian ; that of 
the genus Cymbuliopsis in the North Atlantic and Australasian ; and that of the genus 
Gleba in the North Atlantic and Australasian. 
As with the genera of Gymnosomata, I here collect the data respecting the 
geographical distribution of the genera of Thecosomata in a table which sums up the 
subject in an intelligible way. This table has been made exclusively from the study 
of specimens taken alive, as one cannot take into account the empty shells of the deposits 
in establishing the geographical distribution of pelagic animals like the Pteropoda. 1 
1 With reference to this statement, as well as those made by Dr. Pelseener on p. 116, as to the correspondence 
between the distribution of pelagic organisms on the surface and their dead remains on the bottom, I may state that 
in almost all instances when these remains have been found on the bottom of the ocean, further researches have shown 
the presence of the living animals in the surface waters at all events at some period of the year. — J. M. 
