788 SUMMARY OF CURRENT RESEARCHES RELATING TO 



or shells. Balloon-like in shape it sometimes contains air. ami breaking 

 away floats on the surface of the sea. It lias heen accused of thus lifting 

 ami transporting young oysters from their culture beds. 



Dichotomosiphon and Mischococcus.* — J. Virieux publishes a note 

 on Dichotomosiphon tuberosus (A. Br.) Ernst and Mischococcus confervicola 

 Naeg. The former plant, new to France, he found in good fruiting con- 

 dition near Besancon. He also treats of Mischococcus, which had nor 

 heen recorded for France except once in the north. 



Freshwater Algae of the Clyde Area.f — R. Garry publishes some 

 recent additions to the freshwater algas of the Clyde area. New to the 

 region are the following : — Bulboclisete mirabilis, Microthamaium Kuetz- 

 ingianum, Microspora floccosa, Spirogyra belUs,S.nitida, Ghoaspis stictica, 

 Spirotsenia condensata, Desmidium swartzii. 



Pleurococcus sulphurarius.i — E. Clerici writes on some specimens 

 (fathered in the Valle del Bove on Mount Etna. On one of the pieces of 

 lava found near a f umarole was a patch of green alga, possibly the un- 

 described Protococcus vulcanicus recorded by Cesati from the Solfatara 

 of Pozzuoli in 1869, and described by Galdieri in 1899 under the name 

 Pleurococcus sulphur arius. 



Clathrocystis.§ — G. B. De Toni writes about an extraordinary 

 development in Lago di Como of an alga harmful to fishing. This 

 occurred in October 1909, and was due to Glathrocystis serur/inosa. 

 Similar developments have been recorded by Besaua for 1898 and 1908. 



Breaking of the Meres. || — J. Burton publishes a note on two in- 

 stances of the "breaking of the. meres," one in a pond at Totteridge on 

 July 10, 1909, the other in the Welsh Harp reservoir. The algae con- 

 cerned were Oscillator ia decolor ata West in the former case, and 0. Agardhii 

 Gom. in the second. 



Fossil Diatoms in Italy. % — E. Clerici gives an account of the species 

 found in the diatomaceous earth occurring near Lago di Avigliana — some 

 fifty species chiefly belonging to the genera Gymbella, JYavicida, Gom- 

 phonema, Epithemia. 



He also ** points out the importance which diatoms present in the 

 study of geology. He indicates, for instance, three types of diatomif erous 

 strata in the environs of Rome (1) with brackish species ; (2) with 

 Cyclotellea?, especially Stephanodiscus Astrsea ; (3) with species of 

 Epithciii ia prevalent. 



He also ft gives a microscopic analysis of the calcareous deposit at 



* Bull. Soc. Hist. Nat. Doubs, No. 19 (Jan. 1910) (1 pi.), 

 t ( Glasgow Nat., ii. (1909) pp. 13-14. 

 X Boll. Soc. Geol. Ital., xxviii: (1910) pp. ccvi-vii (1 pi.), 

 ij Kevista Mensile di Pesca e Idrobiologia, v. (1910). 

 Journ. Quekett Micr. Club, xi. (1910) pp. 115-20. See also Nuov. Notar., 

 xxii. (1911) p. 90. 



^1 Boll. Soc. Geol. Ital., xxvi. pp. cxliii-iv (1 pi.). 

 ** Boll. Soc. Geol. Ital., xxviii. (1910) pp. 649-76. 

 ft Boll. Soc. GeoL.Ital., xxvi. pp. 557-66 (1 pi.). 



