238 



REPORT 1868. 



Trochus amabilis is another case, assuming that it originated from Margarita ? 

 maculata of Searles Wood. 



Professor Dickie has been good enough to report on some Diatoms from 

 the insides of a quantity of Echinus Norvegicus, which were dredged at a depth 

 of 78 fathoms about forty miles from the east coast of Shetland. He says 

 they are chiefly Navicula did y ma, Coscinodiscus excentricus, C. minor, Acti- 

 noci/clus undulatus, and Melosira sulcata, with fewer of M. nummuloides and 

 Nitzsohia angularis, all marine ; also a few freshwater Cocconema lanceolatum, 

 Sunrella minuta, and fragments of a Pinnularia. And he adds that long ago 

 he recorded the occurrence of freshwater Diatomaceas mixed with marine 

 species from the stomachs of Ascidice taken in deep water off Aberdeen. The 

 freshwater Diatoms must evidently have been carried by a stream into the sea, 

 and transported by the tide to the place where they sunk to the bottom, and 

 were swallowed by the indiscriminating Echini and Ascidice. Diatoms inhabit 

 the surface only of the water, and Globigerina and other Foraminifera not of 

 a fixed or sessile nature "have been observed by Major Owen and myself 

 to float when alive within a few inches from the surface. Dr. Wallich found 

 the microscopic organisms which he called coccosphercs " profusely in a living, 

 or perhaps it would be more safe to say a recent, condition in material col- 

 lected at the surface of the open seas of the tropics." Coccospheres and free 

 Foraminifera cover the bed of the Atlantic at enormous depths. The occur- 

 rence, therefore, of such organisms on the floor of the ocean at such depths 

 does not prove that they ever lived there. I should rather be inclined to 

 believe that they dropped to the bottom of the sea when dead or after having 

 passed through the stomachs of other animals which had fed on them. 



A few small fishes were caught in the dredge at depths of from 90 to 100 

 fathoms. Dr. Giinther reports that they belong to the undermentioned spe- 

 cies: Callionymus maculatus (Bonap.), Gobius Jeffrey sii (Giinth.), young, 

 Cyclopterus lumpus (L.), young, Lejpadog aster bimaculatus (Penn.), and 

 Rhombus Norvegicus (Giinth.), young. He remarks that the last-named 

 species is new to the British fauna, having been hitherto known from the 

 coast of Norway only. 



Mr. Norman will report on the Crustacea, Tunicata, Polyzoa, Hydrozoa, 

 Echinoderms, Actinozoa, and Sponges, Dr. M'Intosh on the Annelids, and 

 Mr. "Waller on the Foraminifera. 



Mollusca inhabiting the Shetland Isles and the adjacent seas. (See Tables 

 of distribution in * British Conchology,' vols. i.-iv.) 



