LIST OF RECENT AV0RK8, ETC. 209 



In Lake Baikal remarkable results have been obtained by an 

 exploration of its depths, in making known fauna essentially 

 different from that of the surface. Messrs. D^'bowski and 

 Godlewski obtained at or within 10 metres of the surface, the 

 following species : Valvata Baicalensis^ V. Grubii, Baicalia 

 Angarensis^ B. elata, Ghoanomphalua valvatoides, G. Schrencki, 

 AncyluH Sihiriens, A. Ti^Oi^cheli, Unio sp. 



Between 10 and 100 metres they dredged Hydrobia Marten- 

 siana and H. maxima. Commencing with 100 metres Ghoanom- 

 jDhalus Maacki was found. Finallj'^, between 300 and 350 mfetres 

 were obtained the following strange forms : Ghoanomphalus 

 Maacki, Baicalia pidla, Godlewskia turriformia, Trachyhaicalia 

 cai'inato-costata, T.costata, T. carinata, T. contabulata, T. Wrzes- 

 noiuski, Dybowskia ciliata, D. Duthiersi. Curiously enough, 

 some of these exclusively deep-water forms are closel}^ related 

 to the fossilized shells of the genus Tryonia, occurring in 

 countless myriads on the surface of the dried basin of the 

 Colorado Desert of North America. 



List of im,portant recent works and loapers upon the geograj^hical 

 distribution of the mollusca. 



No attempt has been made to render the following list 

 complete ; only some of the most useful or recent publications 

 upon each fauna are enumerated. Woodward's and Fischer's 

 " Manuals," both contain many lists of species characteristic of 

 the various geographical provinces : these may be consulted 

 with advantage by those who are acquainted with the species ; 

 to others they are simply names without import. 



MARINE PROVINCES. 



I. A7'ctic Province: — 



Sars. Mollusca regionis articae Norvegiae. Christiania, 1878. 



Friele. Jan Mayen Mollusca, 1877. 



Middendorff". Malacozoologia Rossica. St. Petersburg, 1847. 



II. Boreal Province : — 



Gould. Report on the Invertebrata of Massachusetts, 2d. 

 Edit. Boston, 1870. 



Dawson. Canadian Naturalist, iii, 158. (Gulf of St. Law- 

 rence). 



Verrill. Report of U. S. Fish Commissioner. Washington, 

 1871-2; 1879. 



Yerrill. Transactions of the Connecticut Academy, v. 



III. Geltic Province : — 



Jeff"reys. British Conchology. 5 vols. London, 1862-1869. 



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