TRANSACTIONS OF THE SECTIONS. 137 



ile suggests that a yacht of, say, 150 tous is the most practically useful size, not 

 being too large to get uudor weigh quickly, and yet of sufficient size to carry stores, 

 gear, a steam-launch, fuel, and engine, the last to ))e equally available for the launch- 

 screw and a winch on the ship's deck. 



Eut he also considers smaller craft to be equallj^ useful in some ways. 



The Committee might be empowered to communicate with the J loyal Yacht 

 Clubs and ask the support of naturalist members ; they might also consider the 

 advisability of voting grants for attachiug " experts " to such squadrons to describe 

 the more perishable animals Sec. on the spot. 



lu conclusion the author points out the assistance to the supply of large aquaria 

 which the development of tastes for dredging would be — yaciits visiting fishing- 

 stations and saving alive the prizes allowed by fishermen to be wasted, dredging 

 with the yachts and boats themselves, making the nearest British port with a 

 valuable cargo in portable tanlcs, and sending them alive to their inland or coast 

 homes. 



Mr. J. Wasdall, of Scarborough, considers that the education of a body of sailors to 

 zoological work, the keeping of a list of them, so that yacht owners might know whore 

 to find such skilled hands, would be one of the valuable results of the labours of such 

 a Committee. The interchange of expensive apparatus and gear would be another. 



On tlie MoJhtsca of Europe compared with those of Eustcrn North America. 

 'By S. GwYN Jeffreys, F.B.S., F.G.S. 



The author had dredged last autumn on the coast of New England, in a steamer 

 provided by the Government of the United States, and had inspected all the prin- 

 cipal collections of Mollusca made in Eastern North America. The author com- 

 pared the Mollusca of Europe with those of Massachusetts. lie estimated the 

 former to contain about 1000 species (viz. 200 land and freshwater, and 800 ma- 

 rine), and the latter to contain about 400 species (viz. 110 land, and freshwater, 

 and 290 marine) ; and he took Mr. Binney's edition of the late Prof. Gould's 

 ' Report on the Mollusca of Massachusetts' as the standard of comparison. That work 

 gives 407 species, of which the author considered 40 to be varieties, leaving 367 

 apparently distinct .species. About 30 species may be added to this number in 

 consequence of the recent researches of Prof. Verrill and Mr. Whiteavcs on the 

 coast of New England and in the Gulf of St. Lawrence. He identified 173 out of 



per cent. ; and ne proauced tabulated lists ot the species in sup- 

 port of his statement. He proposed to account for the distribution of the North- 

 American Mollusca thus identified by showing that the land and freshwater species 

 had probably migrated from Europe to Canada through Northern Asia, and that 

 most of the marine species must have been transported by the Arctic current through 

 Davis's Strait southward to Capo Cod, and the remainder by the Gulf-stream from 

 the Mediterranean and western coasts of tlie Atlantic in a northerly direction. 



On the Theory of the Scientific. Value of Beaxtfi/ in relation to the doctrines 

 of Mr. Dirwin and Mr. Galton. By F. T. Moxr, F.B.O.S. 



Preliminary Beport on JDredyinys in Lalce Ontario. Bi/ H. AtLEYN'E 

 Nicholson-, 31. D., B.Sc, M.aI, F.E.S.E., Professor of katural History 

 in University College, Toronto, 



In this communication the author gave a short preliminary account of a scries 

 of dredgings carried out in June and July in Lake Ontario.' This lake had not, 

 up to this time, been explored by the dredge ; and some valuable facts having been 

 brought to light in Lake Superior in 1871, by systematic dredging, he was there- 

 fore induced to apply to the Government of the Province of Ontario for a grant of 



