410 SUMMARY OF CURRENT RESEARCHES RELATING TO 



large number of bacteria) ; regions round the drain-opening are strongly 

 mesosaprobic {OscUJatoria tenuis, 0. amphibia, 0. chlorina, 0. chaJyhaea, 

 Spirulina Nordstedtii, and Fhormidium autumnale) : while the outer 

 part of the bay is characterized by Oscillatorta Agardhii and Anabsena 

 spiroides. The author puts forward the following proofs of the sapro- 

 phytic nature of the above-mentioned Enteromorpha species: — 1. Where 

 water is badly fouled by the cleaning of tish, E. dathrata occurs in 

 quantity. In other parts it is not present. 2. In the rocky hollows 

 of the outermost sea rocks algi\3 and lichens collect and rot. In such 

 situations low salinity of the water and variations of temperature play 

 no part. 3. In a culture of E. crinita and E. flexuosa swarmspores 

 settled and germinated on the decaying portions of the mother-plant. 

 Outside Tolo Bay the salinity is greater ; and there the mesosaprobic 

 forms of Enteromorpha act as indicators of foul water. 



Halymenia.* — F. S. Collins and M. A. Howe describe four new 

 species of Halymenia from Bermuda, Southern Florida, and North 

 Carolina. One of these, H. bermudensis, is related to H.floridanus J. Ag. 

 Two others, H. Getinaria and IT. pseudofloresia, find their closest affinity 

 in H. floresia Ag. ; and the fourth, H. echinophysa, is allied to H. actino- 

 physa M. A. Howe, and has for its type specimens collected by the 

 " Challenger " Expedition, preserved in the Kew Herbarium and in the 

 British Museum under the name of '•' Kallymenia reniformis.''' The 

 habit and structure of all these four species are described in full detail, 

 and specimens of three of them have been distributed in the Phycotheca 

 Boreali-Americana. 



Lithothamnium tophiforme.t — C Samsonoff-Aruffo has continued 

 her studies among the calcareous fossils of the Geological Museum in 

 Florence, and has found specimens of Lithothamnium tophiforme Unger 

 from Nettuno, Isola di Pianosa, and Bagni di Casciana, in the Amphi- 

 stegina limestone. She describes in detail the structure of those from 

 each locality. Although her plants lack the reproductive organs, which 

 are of importance in their diagnosis, their anatomical structure enables 

 them to be referred to Madame Lemoine's fifth section of Lithothamnium, 

 under L. tophiforme Unger. That species according to Madame Lemoine 

 has as synonyms L. soriferum Kjellman, L. nodidosum Foslie, and 

 L. fornicatum Foslie. The species has been found as a fossil by Unger 

 in the limestone of Leitha ; and living, by Foslie and Kjellman in the 

 N. Atlantic along the coast of Norway, in the White Sea by Gobi, on 

 the Iceland coast by Stroemfelt, and in Greenland by Rosenvinge. The 

 importance of the present record in Mediterranean Pliocene lies in the 

 connecting Unk which it forms between the middle Miocene and the 

 present day. 



* BuU. TorreyBot. Club, xliii. (1916) pp. 169-82. 



■f Atti B. Accad. Lincei, ser. 5, sxv. (1916) pp. 335-9. 



