ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 575 



before. Hagen admits the novelty of the instance in which two extra 

 peristomes are intercalated upside down between the normal peristome 

 and the operculum, but points out that simpler cases of this abnormality 

 have been described for other species — e.g. Gamptothecium lutescens, 

 Btomalothecwm sericeum, and Milium medium — by Giimbel, Schimper, 

 and Lindberg. 



Thallophyta. 



Algae. 



(By Mbs. E. S. Gepp.) 



North American Algae.* — F. S. Collins publishes diagnoses of the 

 new species, etc., issued in the " Phycotheca Boreali- Americana," the 

 first fascicle of which was issued by Collins, Holden and Setchell in 

 February 1895. The author has distributed in that work a number of 

 new species, varieties and forms, and in some cases the diagnosis was 

 printed in tha label, while in others a reference was given to the 

 publication elsewhere. To prevent possible future complications, the de- 

 scriptions in question are reprinted in the present paper, and if the rule 

 for higher plants should be made to hold good for Cryptogams, this 

 article would be the original reference. Eight new species are described, 

 one new combination, and 2G varieties and forms. 



Marine Flora of Jan Mayen. f — F. R. Kjellman gives an account 

 of the marine algas of this island, founded on previous collections and 

 on some plants brought home by Dr. Gran in 1900, and determined by 

 the present author. This collection consists of 26 species, of which 

 seven are new to science, though the author thinks some of them may 

 have been included in other lists under another name. Critical notes 

 are made on most of the species recorded, and following on the systematic 

 treatment is a consideration of the marine, flora of the island from 

 various points of view. The author holds that Jan Mayen must be 

 regarded as a separate province in the Arctic region of geographical 

 distribution, having a certain relationship to Spitzbergen and Greenland. 

 As regards the ecological conditions, nothing is known, but the flora 

 appears to be entirely from deep water. Nothing is recorded of a 

 littoral vegetation. Hauck mentious the occurrence of Fucus evanesce/is 

 at a depth of 20-30 metres, and the same depth is given for Ascophyllum 

 nodosum. The depth at which vegetation begins is said to be 5 metres. 

 Very little is known about the formations, though, from remarks made 

 by Hauck, it may be inferred that species of Laminar ia and of Fucus and 

 Ascophyllum nodosum are common. The author believes that the 

 apparent poverty of the flora of Jan Mayen is due merely to the slight 

 knowledge we have of it. Algae appear to be drifted to the island by 

 currents from the east. 



Marine Algae of the Mediterranean.} — F. Ardissone completes his 

 review of the algae of the Mediterranean, the first part of which was 

 published in 1901, and contained an account of the Rhodophyceaa. The 



* Rhodora, viii. (1906) pp. 104-113. 



t Arkiv f. Botanik,v. (1906) No. 14, pp. 1-30 (3 pis.). 



t Rend. R. 1st. Lombardo Sci. Lett., xxxix. (1906) pp. 156—76. 



