1885. | Zoblogy. 313 
the Australian region. As a rule, however, the species having 
the wider geographical distribution are those from the shallower 
depths. Another exception to this rule is the genus Catenicella, 
rich in species, and almost confined to shallow Australian seas. 
Mollusca— Nature, in reviewing Dr. R. Bergh’s report upon 
the Nudibranchs collected by the Challenger, remarks that few 
shallow water dredgings were made during the cruise, and thus 
it is not strange that only twenty-five species were found. The 
majority of them are Phylliroide and A®olidiadz, and are pela- 
gic; some are littoral,as Fanclus australis, of which a single spe- 
cimen was taken in the Arafura sea. Another, Cuthonella abyssi- 
cola, was taken by the trawl in Farce channel at 608 fathoms. 
Some new Tritoniade and Dorididæ are described, and among 
the latter the most interesting is Bathydoris abyssorum. The body 
of this species is semiglobular, as in the genus Kalinga of Alden 
and Hancock, and it resembles this genus also in having branchie 
composed of several separate branchial tufts, as well as in the 
presence of soft conical papillz onthe back. It has no frontal 
appendage, and a very slightly pronounced dorsal margin, and 
seems to connect the Doridide with the Tritoniade. The only 
specimen was taken in 2425 fathoms in the middle of the Pacific. 
The body of the living animal was gelatinous and transparent, the 
foot dark purple, the tentacles brown, and the gills and other ex- 
ternal organs orange. One specimen only of the Onchidiade, 
O. melanopneumon, was taken in shallow water at Kandara, Fiji. 
Dr. Bergh believes these animals to have no relation to the Nudi- 
branchs,——Mr. J. R: Davis (Nature, Jan. 1), assert that limpets 
have a settled home, for they occupy scars on the rock, often 
sunk to a considerable depth. He marked and watched specimens 
to prove this, and found that, though a marked limpet might 
move about three feet from its scar in any direction, in search of 
food, it always found its way back. A limpet always returns be- 
fore the rising tide reaches it, and roosts with its snout pointing 
in the same direction: Mr. Davis asks what sense is used? Th 
eyes of a limpet, mere sensitive cups, can at most distinguish dif- 
ferent degrees of light intensity ; the examples deprived of their 
tentacles found-their way back, and repeated washing of the track 
with sea-water in order to destroy scent did not prevent the lim- 
been found upon the stalks of fossil Pentacrini. Dr. von Graft 
requests any palzontologist having crinoids under his care to ex- 
amine the specimens, and, if he should notice little pustules at the 
base of the pinnules, to communicate with him. Graff's class 
Stelechopoda embraces the Tardigrades, Linguatulids and My- 
zostomes. The forms before known were characterized by the 
