ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 563 



up well, in the fresh gatherings they were very poorly represented 

 indeed, both in species and numbers. The total number of organisms 

 in the flora amounts to 305, of which 81 are here described as, to a 

 greater or less extent, new forms. Critical notes are appended to most 

 of the records. 



Chlamydomonas.* — M. W. Spargo writes on the genus Ghlamydo- 

 monas, her purpose being to bring together comparatively a number of 

 the American species and to correlate them so far as possible with the 

 better known European species. After a histological discussion of the 

 genus, she describes her technique, which proves satisfactory. A new 

 marine species is then described, G. Moorei, from Woods Hole, Mass. 

 As regards the cilia on a cell of Chlamydomonas, the author finds that 

 their number is not a definite specific character, but depends on circum- 

 stances which have not yet been determined. Also she holds that 

 Carteria Diesing should no longer be considered a genus, since its single 

 hitherto differentiating character has been shown to vary in the same 

 species. She believes that the stigma of Chlamydomonas is a disk-shaped 

 body, the various shapes ascribed to it by authors depending on the 

 various positions of the cell when being examined. The use of the 

 position of the pyrenoid in relation to the longitudinal axis of the cell as 

 a systematic character is an error, as the pyrenoid is in the chromato- 

 phore, which does not fill the centre of the cell, but extends around the 

 cell, within the membrane. Remarks are made on physiological experi- 

 ments. Eleven species are described, of which three are new. 



British Diatoms. f — N. E. Brown describes some diatoms found 

 during a holiday at Tenby. Two species among them were Toxonidea 

 Gregoriana and T. madagascarensis, the latter a new record for Britain. 

 This is figured. Other species found were Pleurosigma lanceolatum, 

 Donkinia recta, Amphora obtusa, and Nitzschia virgata. The author 

 discusses the diamond-dotting of these species, which has been incorrectly 

 described. His own careful and exact measurements show the number 

 of striae on his specimens to be about as follows : — Toxonidea Gregoriana 

 48.000-52,000 ; T. madagascarensis 56,000 ; Pleurosigma lanceolatum 

 56,000-60,000; Donkinia recta 60,000-64,000; Amphora obtusa 64,000. 

 He points out that the striae on A. obtusa are very difficult to resolve 

 with a dry lens. 



Polymorphism of certain Antarctic Diatoms.! — L. Mangin writes 

 on the polymorphism of certain Antarctic diatoms collected during the 

 second French expedition in the ' Pourquoi-pas ? ' The first instance he 

 gives is that of his new species Biddulphia polymorphs observed by Van 

 Heurck in material collected by the ' Belgica.' Van Heurck described 

 several species and varieties, which according to Mangin are but forms 

 of one and the same species, B. polymorpha. This is amply proved by 

 the presence of several of the so-called species in the same chain. The 



* Washington Univ. Studies, pt. 1, i. (1913) pp. 65-88 (1 pi.). 

 + English Mechanic, c. No. 2584 (1914) p. 213 (1 fig.). 

 + Comptes Rendus, clix. (1914) pp. 476-84 (figs.). 



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