2 SIR CHARLES ELIOT. 
species of each genus being much smaller than the first. The differences in the radulze 
may be due to growth, for in both genera the teeth near the rhachis are very irregular 
and undefined in outline. 
With the exception of Tritonia challengeriana, already recorded from the west coast 
of Patagonia, all the forms appear to be new. Some uncertainty must exist about Doto 
antarctica, which greatly resembles Doto fragilis, but there are some points of difference 
and it seems safer to create a new species, for it is a considerable assumption to take for 
granted that similar forms from northern and southern seas are specifically identical. 
The Nudibranchiata of the Arctic and Antarctic oceans with their neighbouring 
waters show considerable general resemblances, as far as the faunas are known. There 
is a marked scarcity of Dorids and a preponderance of Tritonids and Aeolids. It must 
be remembered, however, that Dorids are most abundant under large stones in the littoral 
zone, and that even if they exist in such localities on ice-bound shores, they are not 
likely to be brought up by the dredge. But it would seem that even in accessible 
waters they decrease in numbers towards the extreme south. A collection of Nudi- 
branchs made in the Falkland Islands contains only five Dorids referable to two 
species, but nearly forty Aeolids, referable to about four species, and seven Tritonids. 
The ‘ Belgica’ obtained only Tergipes antarcticus. The present collection and_that 
made by the Scottish National Antarctic Expedition have together yielded eleven 
specimens of Tritonids, eight of Notaeolidia, one of Doto, eight of various Aeolids, two 
of Bathydoris, and no ordinary Dorids at all. Acanthodoris, however (which with 
the allied Adalaria has been found far north in both the Pacific and Atlantic), is 
recorded from New Zealand and Cape Horn (Rochebrune and Mabille), and probably 
extends further south. Archidoris is recorded from Kerguelen Island, Cape Adare 
and Wandel Island.* 
The two collections are too small to warrant any conclusions as to the absence of 
forms which are not represented, but, as far as they go, they indicate that the Arctic 
and Antarctic Nudibranchs are similar rather than identical. As for species, Dr. Bergh 
regards an Acanthodoris found in New Zealand as a variety of A. pilosa, and the 
animal here described as Doto antaretica may possibly be a variety of D. fragilis. The 
genera Tritonia and Bathydoris are common to both seas, and are also recorded from 
intermediate points, Bathydoris only from great depths. Tritoniella, Tritoniopsis, and 
Notaeolidia are recorded only from the south, while Dendronotus and Campaspe, 
though frequent in both the North Atlantic and North Pacific, and extending into the 
Polar regions, are not recorded from further south than the Bay of Biscay and 
California. The Antarctic Aeolids hitherto collected are allied to Cratena or Galvina, 
no Facelinide or Coryphellide having been found. It is remarkable that in all of 
them the vent is dorsal, not lateral. 
panties by ahah Analy Bociuen GU GER IGS CT ne 
tuberculata ; Guy-Valvoria [sic.—Ed.], a new genus of the Aeolidide ; Charcotia, which a tl i 
of the characters of the Tritoniide and Tethymelibide ; and Notacolidia gigas. a ca 
