116 Bibliographical Notices. 



Gampagnes Scientifiques clu Yacht Monegasque V Hirondelle. Trois- 

 ieme Annee, 1887. Excursions Zoologiques clans les iles cle Fayal 

 et cle San Miguel (Azores). Par Jules de Guekne. 8vo. Paris : 

 Gauthier-Viliars et fils, 1888. 



His Highness Prince Albert of Monaco, following the example of 

 some few less distinguished yachtsmen, zealously devotes himself 

 during his voyages to the investigation of various scientific questions. 

 As a rule, perhaps from a feeling that in these investigations he is 

 to be regarded as representing his principality, and with a laudable 

 desire to make it famous for something more than the worship of 

 the black and the red with which the name of Monaco is generally 

 associated in the minds of men, he has generally directed his efforts 

 to the class of researches usually carried on by Government expe- 

 ditions, and the currents of the North Atlantic, especially the Gulf- 

 stream, the largest of them all, have attracted most of his attention. 

 But while these physical questions have formed the main objects of 

 his voyages, other things have not been neglected, and he has 

 always secured the companionship of two or three naturalists to 

 assist him in working out such zoological problems as may present 

 themselves for solution during the expeditions. 



Among these M. Jules de Guerne, the author of the work whose 

 title stands at the head of this notice, seems to have always occupied 

 a place, as we find him contributing papers upon the zoological 

 results of both the Prince's previous voyages in 1885 and 1886. In 

 1887 the great object of the expedition was a further investigation 

 of the currents of the Atlantic ; but a short stay at the Azores was 

 taken advantage of by M. de Guerne for the purpose of studying the 

 freshwater fauna of those islands. His results, as here given, are 

 exceedingly interesting. 



In such islands as the Azores of course the amount of fresh 

 "water is comparatively limited, consisting chiefly of small lakes 

 generally situated in the hollows formed by extinct volcanic craters. 

 In these the author instituted researches analogous to those which 

 have furnished such interesting results in the case of various Euro- 

 pean lakes ; and these were of the more importance in the case of 

 the Azores, isolated specks in the midst of the ocean, because from 

 the recent date at which the water of these lakes must have accu- 

 mulated, the time for the introduction of freshwater organisms 

 must have been very limited. It is therefore interesting to find 

 that, as in the case of the majority of the terrestrial animals, the 

 forms are decidedly European, although it must be admitted that in 

 some cases the species are very generally distributed. 



A very few species are regarded by the author as new to science. 

 They include a minute Gasteropod, referred with doubt to the genus 

 Hydrohia, and named H. ? euaaescens. It seems still to be doubtful, 

 however, whether this mollusk may not be a juvenile form. The 

 only Lamellibranchiate mollusk obtained is also described as a new 

 species, under the name of Pisidium Dahnegi, which, from the re- 

 marks made upon it, would seem to be most nearly related to the 



