ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 283 



Reproductive organs are unknown. The alga; were probably attached 

 species of a coastal region. The form is much smaller than that of 

 living species. 



Fossil Algae.* — A. Rothpletz discusses, among other fossils, the 

 calcareous algre of Gottland. They are all encrusted species, belonging 

 to different families, mostly to Siphonales. Solenospora is represented 

 by four species, of which one is new. The other described species of 

 the genus are criticized. A new genus, Hedstromia, is described ; it is 

 allied to Halimeda and contains two species. Sphserocodium is repre- 

 sented by several species. Then follows the Siphonese v&rtidillatse, in 

 which again a new species is described. The author then discusses the 

 formation of ooliths. 



Swollen Cells in Antithamnion. f — B. Schussnig writes on the 

 bladder-like cells of Antithamnion, which he agrees with Nestler in 

 regarding as branches (Kurztriebe). As regards their function, he does 

 not consider that they have any connexion with light, nor that they are 

 storage cells. He regards them as floats. Their less dense contents 

 point to this, also their hyaline appearance, and the brilliance which 

 indicates high refraction. Glycerin caused no crumpling, which shows 

 impermeability to sea-water. The author considers that the physical 

 structure of the membrane of the bladder-like cells acts in the same way 

 as the tissue of the bladders in Sargassum. Also he regards the position 

 and frequency of these cells, as well as the thallus structure, as fitting in 

 with his theory. Another point he makes is the great number of 

 bladder-cells, which are associated with plentiful formation of tetraspores, 

 thus lightening the otherwise heavy tetrasporic branch. 



Ceramothamnion adriaticum4 — B. Schussnig writes on the red 

 alga Ceramothamnion adriaticiim Schiller. It forms long filaments, 

 which grow by means of an apical cell, dividing off its segments hori- 

 zontally. Every joint of the main axis cuts off a number of cortical 

 cells, so that the thallus resembles morphologically a simple Geramium. 

 Branching is rare, mainly adventitious, occasionally forked. The plants, 

 which below throw out creeping shoots, form plentiful rhizoids. The 

 protoplasm which lies against the wall of the axial cells contains elongated 

 light pink lobed chromatophores. In the cortical cells the lobes appear 

 broad. The tetraspore-mother-cell arises from a basal cell of a small 

 cortical branchlet. As this process is often repeated in close proximity, 

 it sometimes occurs that three tetrasporangia of different ages lie close 

 together. The author found' no other organs of reproduction. He 

 regards the mode of cortication as well as the free position of the tetra- 

 sporangia as primitive characters, and considers that morphologically it 



* Sver. Geol. Undcrsokn. Afkandl. och Uppsats, Stockholm, 1913, No. 10, 

 57 pp. (9 pis. and 1 map). See also Bot. Centralbl., cxxviii. (1915) p. 92. 



t Oesterr. Bot. Zeitschr., 1914, pp. 1-8 (1 pi. and 4 text-figs.). See also Bot. 

 Centralbl., cxxviii. (1914) p. 126. 



\ Oesterr. Bot. Zeitschr., 1914, pp. 85-93 (1 pi. and 3 figs, in text). See also 

 Bot. Centralbl., cxxviii. (1914) p. 127. 



