ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 703 



also, and he describes once more his successful manner of procedure. 

 The form of the eyespot in H. pluviaUs is very different. In older 

 individuals the club-shape predominates, while in the younger ones the 

 form is that of a sharp-angled, spherical triangle. It lies in the peri- 

 phery of the upper part of the cell, mostly near the equator, and at the 

 same level as the nucleus. The size varies from 2-1;->a(, long by 1-5/x 

 broad, while the average zoospore is about 5 m long. The stigma of 

 H. BiitschUi, as described by Blochmann, lies at the level of the front 

 pyrenoid or even higher, is 2 /x long and half -moon shaped. The author 

 further describes the stigma found in a third species of Hmnatococcus 

 from Drobak in the Christiania fjord, and named by him H. drmbaketisis. 

 It lies below the upper pyrenoid and somewhat in front of the equator. 

 The length is about 2 fj., the width up to 1 /*, and the form resembles 

 that of the stigma of H. pluviaUs. The position of the stigma is 

 constant in all 3 species during the growth of the swarm-cells ; but 

 before vegetative division, it shifts right up to the front end in 

 H. BiitschUi and E. drcebake/isis, while in H. pluviaUs it retains its 

 position throughout. 



Literature of Cyanophyceae.* — K. Zacharias writes a review of the 

 Hterature which has appeared since 1904 treating of Cyanophycese, the 

 most important of which is Fischer's Zelle der Cyanophyceen.t The 

 latest results and opinions of authors are summarised in detail under the 

 headings : Peripheral protoplasm ; the limiting of the central body ; 

 occurrence of glycogen, granular contents, cell-division. As regards the 

 granular contents, two kinds appear to be commonly present : (1) Cyano- 

 phycin grains in the peripheral protoplasm ; (2) central grains in the 

 central body. Statements regarding the presence of grains in other 

 parts of the cell require confirmation. 



Peridiniese of the Pacific. — C. A. Kofoid | describes the structure of 

 Goniaulax iriacantha Jorg., an arctic form previously imperfectly known 

 and incorrectly figured. He also§ describes TriposoUnia, a new genus of 

 Dinophysidge, with eight species, five of which are new. He discusses 

 the specific characters and points out the significance of the asymmetry 

 of the genus. He also reports || upon the PeridinieaB collected in the 

 eastern tropical Pacific during the cruise of the United States Fish 

 Commission steamer 'Albatross' in the winter months of l!)04-5. He 

 describes and figures 99 new species. He discusseslf the limitations of 

 isolation in the origin of species, and draws some arguments from the 

 coincident abundance of species of Ceratium in the Pacific off San Diego 

 in California. He also gives** descriptions and figures of 22 new forms 

 of plankton collected off San Diego since 1901. These include 19 

 species and 2 sub-species new to science. 



* Bot. Zeit., Ixv. (1907) pp. 265-87. t Op. cit., Ixiii., 1905. 



X Zool. Anzeig., xxx. (1906) pp. 102-5 (figs.). 



§ Univ. of California Publications (Zoology) iii. (1906) pp. 93-133 (3 pis. 

 and- figs.). 



II Bull. Mus. Comp. Zool. Harvard, 1. (1907) pp. 163-207 (17 pis. and map). 

 t Science, xxv. (1907) pp. 500-6. 

 ** Univ. of California Publications (Zoology) iii. (1907) pp. 299-340 (12 pis.). 



