762 RECORD OF CURRENT RESEARCHES RELATING TO 



with melting ice. Hasmatococcus vegetates at very low temperatures, 

 even beneath ice. 



Marine Algse of the Gulf of Naples.* — P. Falkenbcrg gives a 

 list of the marine alga3 found at Naples, which will be exceedingly 

 useful to the student of these forms who visits that region : the most 

 complete work on the subject is very old, inasmuch as it was published 

 in 1823 — the ' Hydrophytologia Eegni Neapolitani' of the famous 

 Delle Chiaje. 



The systematic portion of the essay is based upon Agardh's work 

 on these forms ; but there is also given in addition, notes on the 

 times at which the algas were found and of their times of fructifica- 

 tion, while the localities of the rarer forms are also indicated. The 

 list contains the enumeration of six algfe from Messina, which are not 

 mentioned in Langenbach's list ; some of these are new to the flora of 

 the Mediterranean. 



New Diatoms.t — P. Eichter records two new fresh-water species 

 of Diatomacea3 belonging to the genus Homceocladia, hitherto known 

 as an almost entirely marine genus, which he calls H. germanica and 

 H. conferta. They were found in a mill-stream near Leij)zig, 

 growing amongst Cladophora, within reach of the spray of the mill- 

 wheel. The ground in the neighbourhood is strongly impregnated 

 with salt. 



Terrestrial Diatoms.:j: — M. J. Deby recalls the inquiry of 

 Ehrenberg § as to how it was that amongst the 400 species of diatoms 

 found in the environs of Berlin, the two species which were most 

 common in the atmospheric " dust " of all parts of the world, and at 

 all elevations above the level of the sea, Eunotia (NitzscJiia) ampJujoxis 

 and Pinmilaria horcalis, and which were also those met with most 

 frequently in dust deposits at Berlin, were of the greatest rarity in a 

 living state on the ground. He points out that few naturalists have 

 occupied themselves with the search for diatoms outside their usual 

 habitat in the sea or fresh water, with the exception of the late Mr. 

 Walker Arnott, in whose collection are two gatherings obtained from 

 moss growing on elms at Ulverston and in Perthshire. Mr. C. John- 

 son, of Lancaster, and the Eev. — Cresswell, of Teignmouth, have 

 also made similar collections. 



The following were the species obtained : — OrtJwsira mirabilis, 0. 

 spinosa, Navicula miitica, N. pnsilla, Pinmilaria horealis, Nitzschia 

 ampliyoxis, Amphora affinis, Achnantidium coardatum. 



These species, and probably many others, M. Deby considers to 

 be essentially muscicole, living habitually on trees and in other places 

 exposed to atmospheric vicissitudes ; and he recommends the methodical 

 washing of mosses wherever foruid, with a view of forming a list of 

 Bacillaria which they contain in a living state. The presence of these 

 species in the mosses of trees explains the fact of their presence 



* ' Mitt. Zool. Stat. Neapel,' i. (1879) p. 217. 



t ' Hedwigia,' xviii. (1879) p. 61. 



X ' Bull. Soc. Beige Micr.,' v. (1879). 



§ ' Uebersicht der seit 1847 fortgesetzten Unteiaucliuugen, &c.' (1871) p. 102. 



