ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 85 



recognized five different species, one Lithothamnium, three Lithophyllum 

 and one Amphiroa. Three of these were determined specifically, and 

 the remaining two are probably new, but too fragmentary to allow of 

 sufficient description to establish new species. Notes are given on each 

 of the five species, with such distinguishing characters as can be 

 discerned. This investigation proves that calcareous algge continue to 

 this day, in the constitution of marine deposits, the more or less 

 preponderant role that they have played in all geological epochs since 

 Silurian times. This is the first record of calcareous algee from the 

 Comoro Archipelago, though the neighbouring regions, Seychelles, 

 Amirante, Saya de Malha and Mauritius, are comparatively well known 

 Irom that point of view. E. S. G. 



Note on an Algal Limestone from Angola.— Mrs. M. F. Romanes 



'{Trans. Roy. Soc. Edinb., 1916, 51, 581-4, 1 pi.). A description of 

 Tock-specimens from the Albian beds near Lobito Bay in the province 

 of Benguella, Angola, collected by J. W. Gregory. Two new calcareous 

 algse are figured — Girvanella minima and Lithothamnion angolense. 



A. G. 



New Species of Fucus, F. dichotomus Sauv. — C. Sauvageau 

 iC. R. Acad. Sci. Paris, 1915, 160, 557-9). A description of this^ 

 new species of Fucus, which has been found on the " brandes " border- 

 ing certain oyster beds, now covered with sand and abandoned, in the 

 harbour of Arcachon. F. dichotomus grows only for a few months, and 

 is distinguished from F. platycarpus by its flabellate ramification in- 

 volving the simultaneity and abundance of the receptacles, and by the 

 cylindrical form of the receptacles. The plant being fixed, the adven- 

 titious shoots do not propagate the species, but preserve it ; and to 

 them is due the extension of life in certain individuals to one or even 

 perhaps two years. E. S. G. 



Availability of the Nitrogen in Pacific Coast Kelps. — G. R. 



■Stewart {Journ. Agric. Research, Washington, 4, 1915, 21-38). 

 The value of dried and ground kelp as a fertilizer varies with the 

 species. The nitrogen of Kereocystis Luetkeana is relatively very 

 available, while that of Pelagophycus porra is not. That of Macrocystis 

 pyrifera is slowly yielded in the soil, and more quickly when the kelp is 

 fresh or only partially dried. Removal of the salts from the alga does 

 not hasten its decomposition. For easy grinding the Macrocystis must 

 be dried crisp, but should not be scorched. The presence of kelp ia 

 unlikely to interfere with the ammonification or nitrification going on 

 in the soil. A. G. 



Fungi. 



Repeated Zoospore Emergence in Dictyuchus. — William H. 

 Weston {Bot Gaz., 1919, 68, 287-96, 1 pL, 1 fig.). The fungus 

 described appeared in a culture of moist sand, leaves and other debris 

 iaken from a shaded brook near Great Bacrington, Massachusetts. It 



