498 Miscellaneous. 



the scalpel. It is only by the study of a type in w Inch the cement- 

 glands may be far removed from the mesentery and the cloaca that 

 we can see whether the nervous ganglion would entirely break off 

 its relations with the latter two organs and follow the cement- 

 glands in their displacement. — Comptes liendus, April 13, 1885, 

 p. 1010. 



On the Pelagic Fauna of the Baltic Sea and Gulf of Finland. 

 By MM. G. Pouchet and J. de Guerne. 



The authors received from the Hereditary Prince of Monaco the 

 materials obtained by him with the towing-net during a yacht 

 voyage in the Baltic in 1884. His operations were carried on from 

 54° 59' N. lat. and 17° 8' E. long., as far as the bottom of the Gulf 

 of Finland. They extended from the 14th August to the 15th 

 September ; the weather was fine and the sun generally shining, 

 and the surface-temperatures of the sea when the collecting was 

 carried on, i. e. from 9 a.m. to 4 p.m., were between 14° and 10° C. 

 (57°'2-G0°-8 P.). 



The chief materials obtained in the Baltic consisted of Cladocerous 

 and Copepod Crustaceans, with a great quantity of small algus. 

 The latter cover the whole extent of the basin included between 

 Gothland, Prussia, and the entrance of the Gulf of Finland. They 

 give the water of the Baltic its characteristic olive-green colour. 



In the Gulf of Finland there were found freshwater Crustaceans 

 distinctly characterized as lacustrine pelagic (Forel), such as Cyclops 

 quadricornis, Daphnella brachyura, Daphnia quadra ngzda, and Bos- 

 mina longirostris. The last-named species forms three fourths of 

 the mass of animals obtained in these waters. It is found associ- 

 ated with Hyalodaphnia laihlbergiensis and a marine pelagic form, 

 Evadne Nordmanni, which becomes more and more abundant as the 

 saltness of the water increases. Towards the south the Evadne is 

 gradually substituted for the Bosmina, which, however, occurs 

 beyond Danzig, and the marine Bosmina taken in the Sound by 

 Muller and at Kiel by Mbbius is probably only a variety of that of 

 the Gulf of Finland. 



Towards Gothland the marine Copepoda begin to be numerous, 

 forming about one third of the animals captured. The remainder 

 consists chiefly of the Evadne. Further south, in latitude 54° 59' 

 N., some embryonic Laniellibranchs make their appearance ; but 

 their scarcity contrasts with the abundance of such larva? in the 

 ocean and the Mediterranean. A single doubtful specimen of a Peri- 

 dinian (Dinophysis) occurred. Tcmora velox, well known as an 

 inhabitant of brackish water, occurs everywhere. 



The authors sum up as follows the general results of their inves- 

 tigations : — " It seems to us," they say, " that the pelagic fauna of 

 the Gulf of Finland resembles in general character that of the great 



