446 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
“ British Area” in Marine Zoology.* — Canon A. M. Norman has 
an interesting paper on this vexed question. He defines it as bounded 
on the south by 49° 30' N., terminating at 5° 0' W. — that is, midway 
between the Land’s End and Brest. The mid-channel should be the 
boundary round the south and south-east coast, until, nearly opposite 
the Naze, we obtain a mid-channel at 2° 30' E., and that longitude may 
be taken as the boundary through the North Sea and past Shetland. 
The northern boundary is more complex ; it may start from the west at 
60° N., and proceed eastwards till a point about midway between Cape 
Wrath and Faroe is met at 5° O' W. ; thence a line should be taken due 
north-east past Shetland, until 1° 0' W. is reached, whence the line 
should go due east to 2° 30' E. The western boundary has no limits ; 
it is the slope of that part of the continent of Europe of which our 
islands are the outliers, and descends to the base of the continent at 
1500 fathoms. The author details his reasons for suggesting these 
boundaries, and criticizes the report of the British Association (1888) 
Committee, of which he was chairman, but to which at the time he was 
not able to give the necessary attention. 
B. INVERTEBRATA. 
Marine Invertebrate Fauna of the Gulf of Manaar. — In a report on 
the Pearl and Chank Fisheries,! published by the Government of Madras, 
Mr. E. Thurston gives a preliminary account of the marine fauna of the 
Gulf of Manaar ; the sponges, echinoderms, Crustacea, and Mollusca have 
been worked out by specialists ; there is also a list of the Ccelenterata. 
New Invertebrates from the Coast of California.! — Mr. J. W. 
Fewkes gives descriptions of various new genera and species of Inverte- 
brates, which he collected off the coast of California ; especial attention 
was directed to the MedusEe. 
Heliotropism of Nauplii and Movements of Pelagic Animals.§ — 
Mr. T. T. Groom and Dr. J. Loeb have made a number of experiments 
on the Nauplii of Balanus jperforatus with the object of testing their 
heliotropism and of investigating the causes of the migrations of pelagic 
animals to or from the surface of the sea. They come to the conclusion 
that the periodical daily migrations of pelagic animals are due to 
heliotropism, or, in other words, are directed by the rays of light; 
this heliotropism is in the evening (in faint light) positive, and in the 
morning (in strong light) negative. The directive influence of a source 
of heat is slight in comparison with that of a source of light, so that the 
heating of the surface by day and its cooling by night do not play any 
essential part in the periodical migrations of animals. 
Mollusca. 
Revision of British Mollusca. |] — The Rev. Canon Norman has com- 
menced the publication of a revision of British Mollusca. In the present 
paper the Cephalopoda are dealt with, and a new arrangement of the 
group is proposed. It is based primarily upon sexual distinctions. The 
* Ann. and Mag. Nat. Hist., v. (1890) pp. 345-53 (1 map). 
f Madras, 1890, 8vo, pp. 69-89. 
% ‘ Zoological Excursions,’ i., Boston, 1889, 8vo, 50 pp., 7 pis. 
§ Biol. Centralbl., x. (1890) pp. 160-77 ; 219 and 20. 
|| Ann. and Mag. Nat. Hist., v. (1890) pp. 452-84. 
