. ZOOLOGY. AND BOTANY, MICROSCOPY, ETC. 593- 



Antarctic and Sub-antarctic Marine Algae.* — C. Skottsberg pub- 

 lishes liis report on the Pha3ophyce33 collected by him on the Swedish . 

 Antarctic Expedition in the following localities : — Sub-antarctic South 

 America, Falkland Islands, South Georgia, Kerguelen and neighbouring 

 islands, Tasmania, New Zealand and islands to the south, Graham's-land, 

 South Shetland and South Orkneys, Victoria-land. He records 59 species, 

 including several new to science, 4 new genera, and 1 new family, 

 Ascoseiracete, which may, in the author's opinion, prove to be the 

 oldest known type of Cyclosporete. Many of the species recorded are 

 discussed at great length, notably MacrocysUs, which is treated of from 

 a morphological, anatomical, and systematic point of view. Another 

 note deals with the inter-relations of the various genera belonging to the 

 Lessonia group. Under the heading of general remarks, many interest- 

 ing facts are noted, one of them being that the marine flora appears 

 to be well developed in winter, even as regards the small epiphytic 

 forms, and this applies both to the littoral and sub-littoral regions. 

 Most of the species appear also to be fertile in winter. The paper is well 

 illustrated by text figures and plates. 



Sargassum lunense Cald.t — This species was collected at Spezia by 

 L. Caldesi, and distributed by him in the Erb. Critt. Ital., No. 819 

 (1319) and in Eabenhorst's Alg. Europ., No. 1950. A. de Toni wiites 

 an account of this species, and discusses its affinities. In the form of the 

 leaves, the absence of pores, size and disposition of the aerocysts, and 

 form of the receptacles, it resembles S. Hornschuchii Ag., and differs 

 from S. liiiifolmm Ag. The author considers that S. lu/wise represents 

 a long-leaved form of S. Hornschuchii, and suggests that special con- 

 ditions in the Gulf of Spezia may have contributed to the determination 

 of this variety — an hypothesis that could only be proved by experiment., 



Dictyota dichotoma.| — W. D. Hoyt has made a careful study of the 

 periodicity shown in the production of the sexual cells of this alga, 

 at Beaufort, N.C., and compares his results with those of Lloyd 

 Williams, whose experiments were carried out at Bangor, in Wales. He 

 finds that, as on the coasts of Wales and England, D. dichotoma produced 

 at Beaufort its sexual cells at regular intervals, bearing a definite re- 

 lation to the tides. The time of production of these crops, however, 

 differs from that on the coasts of Wales and England, the crops being 

 borne at monthly instead of fortnightly intervals. The assumption 

 that light is the sole factor determining the time of fruiting does not 

 hold for the plants of D. dichotoma growing at Beaufort. Specimens 

 of Dictyota from Jamaica indicate that there, also, the sexual cells are 

 produced in periodic crops, and that periodicity may obtain throughout 

 the genus. The time of fruiting, however, at least in some cases, is 

 different from that of Dictyota at Beaufort. Periodicity in the produc- 

 tion of the sexual cells is not universal among the Dictyotacete. A species 

 of Padina, probably P. Durvilkei Borg., bears antheridial sori of all ages 



* Wiss. Ergebu. Scliwed. SudpolariExped., 1901-3, iv., lief. 6, 172 pp., 10 pis., 

 1 map, 187 figs, in text. 



t Atti Soc. Nat. e Mat. Modeua, ser. 4, ix. (1907) 6 pp. 

 ; Bot. Gazette, xliii. (1907) pp. 383-92. 



