December 15, 1911] 



SCIENCE 



849 



tests that may be applied to determine in the 

 easiest and quickest way what a mineral 

 actually is, and others which, though they may 

 be of equal scientific interest, are unimportant 

 or inapplicable. In its detail the work is 

 monographic and if this is what the author 

 had in mind there is naturally nothing more 

 to be said. Criticisms along these lines are 

 often unfair, being based upon what a re- 

 viewer thinks he has a right to expect rather 

 than what the author intends. Whatever may 

 be one's views on these subjects there is al- 

 ways the comforting reflection that the in- 

 formation given is as accurate as the stage of 

 the science will permit. 



The make-up of the book is the same as 

 that of the first edition. The paper and bind- 

 ing are good, the type clear, and the illus- 

 trations excellent. Petrographers are to be 

 congratulated that so able an authority has 

 found time to put the knowledge gained by 

 many years of study and experience into a 

 form available for students the world over. 

 Geo. p. Merrill 



The British Nudihranchiate Mollusca. By 

 Alder and Hancock; Supplement by Sir 

 Charles Eliot. London, Eay Society 

 (Dulau & Co.) 1910. 4to. Pp. 198. 8 

 plates. 



Of works on this attractive group of mol- 

 lusca, that of Alder and Hancock is par excel- 

 lence, the classic, not only on account of its 

 exquisitely beautiful and accurate plates, but 

 from its monographic character and correct 

 anatomical details. Among the posthumous 

 papers left by the two authors were notes and 

 drawings preliminary to a supplement to the 

 original work. 



To forty-two of these drawings Sir Charles 

 Eliot has added twenty-three new ones and 

 supplied a text, the whole being sent out by 

 the Eay Society with suggestions for the com- 

 pletion of imperfect copies of the old work pos- 

 sessed by individuals interested in the subject. 

 The form is that of the original monograph 

 and the quality of the plates fully equal to 

 that of the first issue. 



But the author has not been satisfied with 



the preparation of a merely descriptive and 

 corrective supplement. He has prefixed to the 

 purely systematic portion chapters on varia- 

 tion and distribution, bionomics, embryology 

 and larval stages, general classification of the 

 group and an exhaustive discussion of the 

 affinities and relationships of the animals con- 

 cerned. These chapters not merely illuminate 

 the subject but are from a merely literary 

 standpoint presented in a form so clear and 

 interesting as to be readable with pleasure by 

 one having only a general knowledge of the 

 mollusca. Such contributions to zoology are 

 likely to invite study of the animals treated, 

 and it is to be wished that works of this 

 quality were more common. 



Wm. H. Dall 



Due d'Orleans, Oampagne arciique de 1907. 

 Par Charles Bulens. Bruxelles. 1910-11. 

 Etude lithologique, par J. Thoulet ; Echino- 

 dermes, par James A. Grieg; Mollusques et 

 Brachiopodes, par Philippe Dautzenberg et 

 Henri Fischer; MicroplanUon des Mers de 

 Barents et de Kara, par le Dr. Alph. Meu- 

 nier; Faune des Mousses: Tardigrades, par 

 Ferd. Eichter; Journal de Bord, et Phys- 

 ique du Glohe, par A. de Gerlache, etc. ; 

 Appendice, Bondages de 1909, par A. de 

 Gerlache; planches et cartes. 

 The steamer Belgica, well known for her ex- 

 plorations in the Antarctic seas, has been 

 engaged in Arctic exploration of late years, 

 under the auspices of the Duke of Orleans and 

 commanded by Commandant A. de Gerlache 

 de Gomery. In 1907 the expedition left the 

 northern coast of Norway at Hammerfest and 

 Vardo, crossed the Murman Sea, circumnavi- 

 gated the southern island of Novaia Zemlia, 

 skirted the west coast of the northern island, 

 penetrated to about latitude 78° in the Polar 

 Sea, taking numerous soundings, before re- 

 turning to Norway. In 1909 hydrographic ex- 

 plorations and soundings were made in the 

 Greenland seas. By the munificence of the 

 patron of the expedition the scientific results 

 of the work are appearing in a series of finely 

 illustrated and beautifully printed quartos. A 

 summary of the titles of those which have 



