238 SUMMARY OF CURRENT RESEARCHES RELATING TO 



' Liguria ' of the Italian navy. The collections were made in the Sea 

 of Arafura, also between Bangkok and Saigon, and in the Gulf of Siam, 

 The plankton of these regions has not been much explored, though 

 occasionally records of diatoms and Peridinieae from the Arafura Sea 

 and Siam appear in literature. As regards the Arafura Sea Catagnymene 

 pelagica Lemm. and Thalassiothrix Frauenfeldii var. javanica Grun. are 

 new records. Many species are new for the Gulf of Siam, where the 

 genera Coscinodiscus and Rhizosolenia constitute the predominant types. 

 Forty-two species are recorded, with critical notes on morphology, 

 systematic position, and geographical distribution. Under Coscinodiscus 

 Sol Wall, the authors discuss the autonomy of the genus Planktoniella 

 Schiitt ; C. prsefextus of Janisch is described in detail ; also C. hipartitus 

 Rattr., of which the authors add to the diagnosis a description of a 

 5-sided individual. 



Marine Diatoms from Iceland. — E. Oestrup reports on 438 

 samples of diatoms collected by various persons on the coasts of Iceland. 

 The habitat and geographical distribution of each species are given, and 

 in many cases notes on the morphology and affinity. Seven new species 

 and some new varieties are described. 



Diatoms of Philadelphia.! — C. S. Boyer publishes an account of 

 the Diatomacete of Philadelphia and vicinity, which he hopes may lead 

 to further research. In the introduction he shortly describes the 

 geology of this district, which is included in the circumference of a 

 circle, having a radius of one hundred miles from Philadelphia and 

 containing the States of New Jersey and Delaware, parts of Pennsylvania 

 and Maryland, and extending eastward to New York Bay and Long 

 Island Sound as far as New Eochelle. The district therefore provides 

 marine, fresh-water and fossil forms. After a few remarks on classifica- 

 tion, the author discusses the morphology and development of the group 

 — the cell, cell-division, reproduction, evolution of form, motion of 

 diatoms, function. Then follows the systematic account, with a short 

 diagnosis appended to each species, and occasionally critical remarks. 

 Every species is figured and to the same scale, namely, 800 diameters. 

 In an appendix the author deals fully with the collection and preparation 

 of diatoms, fresh-water, marine, and fossil, with instructions as to 

 staining, and the preparation of selected mounts. The plates contain 

 700 drawings by the author. 



Swiss Desmids.J — F. Ducellier publishes further additions to his 

 catalogue of the Desmidiacese of Switzerland, collected from the basins 

 of the Lake of Geneva and the Rhone Valley. He has also received 

 material from Canton Valais and from localities in Eastern Switzerland. 

 Many species and forms are added to the Swiss flora, and many of the 

 records are accompanied by morphological and critical observations. 



* Botany of Iceland, i. (1916) pp. 347-94 (1 pi.). See also Nuov. Notar., xxviii. 

 (1917) p. 1.33. 



t The Diatomaceae of Philadelphia and Vicinity. Philadelphia : Lippincott 

 (1916) 143 pp. (40 pis.). 



X Contribution a I'etude de la flora desmidiologique de la Suisse. Geneve : 

 Georg et Cie, i. (1915) (1 pi. and figs, in text). See also Nuov. Notar., xxviii. (1917 

 pp. 122-3. 



