Rare sponge (Porifera: Demospongiae) species from the Mediterranean Sea

Fourteen rare or poorly known sponge species have been found in the Aegean Sea. The species Pachastrissa pathologica, Calthropella stelligera, Weberella verrucosa, Aaptos papillatus, Timea geministellata, Spiroxya heteroclita, Clathria translata, Hymedesmia simillima, Mycale serrulata, Myrmekioderma spelaea, Callyspongia septimaniensis and Ircinia pipetta are new records for the eastern Mediterranean while the species Geodia barretti and Petrosia vansoesti are reported for the first time from the Mediterranean Sea. Information on their morphology, geographical and bathymetrical distribution is given and discussed.

The Hydroids collected by the “Huxley” from the North Side of the Bay of Biscay in August, 1906

The Hydroids collected on the northern edge of the Bay of Biscay during a five days” cruise in August, 1906, by Dr. E. J. Allen, were entrusted to me for examination. I thank my friend Dr. Allen for giving me the opportunity of working through the collection, which contained thirty-seven species, including two new species (Bimeria arborea and Bimeria biscayana) and several rare deep-sea forms.Our knowledge of the area occupied by the British Hydroids has been increased by this cruise. All the species taken at six out of the eight stations have been previously recorded for the British area. It was only at the two stations over 400 fathoms that foreign species occurred. Bathymetrical distribution has also made an advance, as several species were taken at a depth considerably greater than that hitherto recorded for them.

XXIII.—On the Chemical Changes which take place in the Composition of the Sea-Water associated with Blue Muds on the Floor of the Ocean

The numerous analyses of sea-water by Forchhammer previous to 1865, and the later analyses by Dittmar, from samples collected during the “Challenger” Expedition, show that while the salinity—i.e., the amount of dissolved salts contained in 100 parts of seawater—varies greatly in different regions of the ocean, still the composition of these dissolved salts—i.e., the ratio of the constituents of sea-salts—remains practically the same in all the superficial waters of the ocean. Consequently, it is only necessary to determine the chlorine in a definite weight of water to ascertain at once the respective quantities of the other salts present in the sample. Dittmar's examination of the “Challenger” waters has, however, shown that lime is slightly, although distinctly, more abundant in samples of sea-water collected in greater depths than in those samples collected nearer the surface of the ocean, and Dittmar's tables showing the difference between the chlorine calculated from the specific gravity and the chlorine found by analysis point to differences in the composition of the sea-salts, but the observations are relatively so few, these differences so slight, so mixed up with observational errors, and so irregular in their geographical and bathymetrical distribution, that they cannot be said to indicate any general law other than a greater quantity of lime in deep water.

2. Report on the Pishes obtained by Mr J. Murray in Deep Water on the North-West Coast of Scotland, between April 1887 and March 1888

In the present paper I propose to give the result of my examination of the specimens of fishes which were obtained by Mr John Murray on the West Coast of Scotland, whilst dredging during the last eleven months on board of the “Medusa.” Exact observations as to the bathymetrical distribution of British fishes at certain seasons and localities, such as have been obtained during the cruises of the “Medusa,” are much needed, and if methodically carried out for some years, will prove a most valuable contribution to the British fauna, especially if they are supplemented by similar reports on the invertebrates which were collected simultaneously with, and form part of the food of, the fishe.