ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 207 



Sutherland, and is able to give a fuller description of the plant, showing 

 that it is not a Desinid. Finally, the author records Chodatella quadriseta 

 Leuimermann, from Studley Park, Warwickshire. 



Diatoms of the Pacific* — A. Mann reports on the Diatoms collected 

 by the 'Albatross' in the Pacific Ocean during the years 1888-1904. 

 He first describes the methods employed for examining the samples to 

 see if they contained diatoms, as well as the way of mounting the speci- 

 mens. Many of the samples were destitute of diatoms, but some, even 

 as deep as 987 and 1744 fathoms, were particularly rich in them. The 

 importance of the study of diatoms is pointed out as an aid in deter- 

 mining the extent and direction of ocean currents and the origin of the 

 materials composing the sea bottoms. This is partly owing to the inde- 

 structibility of their siliceous remains, those which were formed centuries 

 ago being as well preserved as those of this year's product ; and partly 

 to their extreme minuteness, which allows them to be readily transported 

 by even quite slow ocean currents or surface drifts from their places of 

 origin to remote points and finally sifted down upon the sea bottom. 

 Another point is the enormous number of known species, over 4000, 

 some of which are peculiar to certain localities, there being a tropical, 

 temperate, and frigid flora. The author then goes on to show that 

 certain species were found in certain areas, one instance being that of 

 Biddulphia favus, which forms a practically unbroken chain from Cali- 

 fornia to the Hawaiian Islands. Other important facts concerning the 

 geographical distribution of diatoms are given. The main part of this 

 report consists of an annotated catalogue of genera and species, in which 

 a certain number of new species are described. Synonymy, references 

 to literature, and critical notes follow each record. A list of data of the 

 stations at which diatoms were collected by the ' Albatross,' and a full 

 bibliography complete the work, which is illustrated by 11 plates. 



Distribution of Fucacese on the Coast of Greenland.!— H. Deich- 

 mann and L. K. Rosenvinge write a criticism of a publication by K. J. V. 

 Steenstrup on the question whether the upper limit of the Fucaceae zone 

 can be regarded as indicating variations of sea-level. A short resume 

 is given of the views of this author, and then the views of the present 

 writers are set forth. They deal principally with the " Isf od " or coating 

 of ice which is formed during the winter on the rocks at the edge of the 

 sea, and stretches from a point above high-water mark to a point more 

 or less below it. Deichmann has made a careful study of this Isfod and 

 describes the manner and time of its growth and the effect it has on the 

 algae. He maintains that it is not harmful to the littoral flora as has 

 been supposed, but that the bare zone lying between high-water mark 

 and the lowest limit of terrestrial vegetation is the result of other causes. 

 The zone is too much splashed by sea-water to allow of the successful 

 growth of land plants, while marine algae cannot easily exist where there 

 is an insufficient supply of water. 



The distribution of the Isfod varies in different parts of the region 



* Contrib. U.S. National Herbarium, x. (1907) pp. 215-422 (11 pis.), 

 t Bot. Tiddsk., xxviii. (1907) pp. 171-84 (photos.). (French resume.) 



