Corystes cassivelaunus is a crab of unusually narrow and elongated form, which has received the popular name of “masked crab” from the grotesque resemblance which its sculptured carapace bears to a human face. It is common round all the coasts of the British Isles, and, although normally an inhabitant of the deeper water, is occasionally found at home in sandy pools on the sea shore, and is frequently cast up in hundreds on sandy shores after heavy gales.

IN my report, in the preceding number of this Journal, on my observations in the North Sea, I referred briefly to the problem of the relation between the physical and biological conditions. This problem will afford scope for investigation for some time to come, and the purpose of the present article is to discuss and compare some of the most recent additions to our knowledge of the matter. The paper by Mr. H. N. Dickson, to which I referred in my previous report, was published in the Geographical Journal last March, under the title of “The Movements of the Surface Waters of the North Sea,” and in the Scottish Geographical Journal, in 1894, was published a series of papers by Professor Pettersson on “Swedish Hydrographic Research in the Baltic and the North Seas.” Professor Heincke has discussed the fish fauna of Heligoland, its composition and sources, in an interesting paper in the series issued under the title of “Wissenschaftliche Meeresuntersuchungen,” by the staff of the Biological Station at Heligoland, in association with the Commission for the Investigation of the German Seas, at Kiel. Professor Heincke's paper is contained in Bnd. I., Hft. 1 of this series (1894), and in the same volume are a number of papers dealing on similar lines with other divisions of the marine fauna of the Heligoland Bight.

It will be most convenient and logical to start the present discussion with a consideration of the results of Professor Pettersson's work. He found that the Skagerack and Cattegat were filled with layers of water distinguished from one another by differences of salinity, and that the lower layers entered the channel as under–currents, and could be recognised at the surface somewhere in the North Sea.

A specimen of this somewhat uncommon shark was recently brought to the Laboratory by some fishermen. The following notes on it may be of interest. The fish was taken with a long line baited with mackerel, for conger. It was captured forty miles south of the Mewstone, at a depth of about forty-five fathoms. The specimen was a female, and measured 6 feet 6 inches from the end of the snout to the tip of the tail. The following are the principal other measurements: snout to anterior edge of first dorsal fin, 46 inches; snout to anterior edge of pectoral, 20 inches; the interval between the anterior edge of the pectoral, and the pelvic fin was 26 inches. The first dorsal, which was small, was thus situated immediately above the pelvic. The second dorsal, which was smaller than the first, was situated as nearly as possible midway between the first dorsal and the commencement of the caudal fin. The measurements so far tally with Day's description of the species.

Attention may, however, be drawn to the measurements which follow in connection with the following statement in Day: “Ventral (fin) … commences mid-way between the front gill opening and the end of the caudal fin in elongated forms: or anterior end of the snout and middle of the caudal fin, as observed in the Plymouth and Aberdeen stouter specimens.” (Day's British Fishes, vol. ii. p. 323.)

In my specimen the distance from the front gill opening to the anterior edge of the ventral was 30 inches: thence to the end of the caudal was 33 inches.

Many inhabitants of the sea know as well as men do that oysters are good to eat, and the destruction which they suffer on this account can scarcely be less than that brought about by human agency. Starfishes especially extirpate them in great numbers, and Möbius† maintains that they are the most pernicious enemies which the oyster possesses, although, on the other hand, people have not been wanting who held the destruction of oysters by starfishes to be a fable.

Since the Report on the subject of the Artificial Culture of Sponges was published, some further information of importance relating to the subject has been courteously supplied by the Acting Commissioner of the United States Commission of Fish and Fisheries. This information is in the form of a letter to the United States Commission from Mr. Ralph M. Monroe, of Cocoanut Grove, Biscayne Bay, Florida, to whom the Acting Commissioner refers as “an intelligent and energetic man, whose statements, we think, can be given entire credence” wherein this gentleman gives a detailed account of some experiments conducted by himself at Biscayne Bay, during the years 1889, 1890 and 1891.

There can be no question of the importance of the subjects treated of in this paper; and the results are certainly such as to attract attention. This fact makes it all the more disappointing that the author's method is not calculated to inspire confidence in the accuracy of his conclusions. Before attempting to justify this statement, we may give a brief account of the paper as it stands.

After giving an extensive bibliography, the author passes on in his second chapter to a statement of the method of the investigation, and of the notation by which he finds it necessary to state his results. In the next chapter a table is given showing the extent of variation of particular characters in the species considered, and the degree in which the variations of these same characters in both forms may coincide. The influence of sex and age, and the character and development of the scales, is next treated of, and the following chapter is devoted to a statement of the differences which obtain between the different “local forms” in the North Sea and the Baltic. The rest of the paper is taken up with a consideration of the relations between the local forms and the species, an account of Pleuronectes pseudoflesus, certain morphological and biological observations, and a summary of results. We may now consider the more important parts of this paper in detail,

The method of investigation consisted in examining “a large number” of specimens of each species in respect of no less than thirty-six characters.

As I was able to announce in a postscript to my Report in the last number of the Journal, the Association has secured a small steam fishing yacht, which has already proved exceedingly useful in carrying on the work of the Laboratory. Towards the £600 which was paid for the vessel, a little over £500 has now been subscribed. It is important that the remainder of the sum should be forthcoming, so that it may not be necessary to draw upon our small reserve fund for this purpose.