1898] NOTES AND COMMENTS Loe 
species from the island of Billiton, between Singapore and Java. 
I consider that the distribution of Tunicata as a whole does not 
lend any support to the bipolar hypothesis. On account of the 
admitted want of equivalence between the characters made use of in 
specific and generic diagnosis in the different groups mere lists may 
be deceptive, especially if drawn up and correlated by one man, who 
cannot possibly be a specialist on all groups of marine invertebrata. 
For that reason I now abstain from expressing any opinion except 
in regard to the group of which I have a more intimate knowledge. 
It seems to me that this matter must be settled by specialists in 
each group of animals stating their opinions as to the genetic 
affinities of the northern and southern faunas in their own groups 
quite apart from and uninfluenced by general lists containing other 
groups. The Tunicata instanced by Dr Murray, both in his ‘ Chal- 
lenger Summary’ and in his paper on the ‘ Marine Fauna of the 
Kerguelen Region, help to swell lists that assume rather imposing 
dimensions, but when I examine the case of these species and genera 
of Tunicata individually, I find that the records of occurrence have 
to be added to or modified in such a way as to entirely change the 
nature of their evidence, and show that there is no such close 
resemblance between the northern and southern polar faunas as 
Dr Murray and others have supposed.” 
DrEPp ATLANTIC HOLOTHURIANS 
ANOTHER instance of similarity between N. Atlantic and Pacific 
forms was recently noted by Mr Rémy Perrier in his description 
of the deep-sea holothurians, Elasipoda, dredged by the “ Travail- 
leur” and the “Talisman” (Comptes rendus Acad. Sci., Paris, ¢xxiii., 
pp. 900-903, Nov. 1896). He describes Psychropotes buglossa as 
being a near ally of P. varipes Ludwig, which latter was dredged by 
the “ Albatross” north-west of Cape San Francisco at 1573 fathoms. 
Unfortunately Mr Perrier does not give either localities or depths of 
his new species, nor does he figure them ; this is too much to expect 
in a Preliminary Notice. The chief interest of his paper lies in the 
rearrangement of the species of Peniagone and Scotoplana according 
to the nature of the calcareous spicules, and the establishment on 
the same grounds of a new genus Periamna with triradiate spicules, 
and having as genotype the Peniagone naresi of Théel. 
BIPOLARITY WITH A VENGEANCE 
WE are indebted to Mr Henry Campion of Birmingham for a copy 
of a 48-page treatise— “The Secret of the Poles” (White & 
Pike, price 1s.). Mr Campion recognises the impossibility of man 
ever reaching either pole; at the same time he appreciates the great 
importance that such an investigation would have, and does his 
