ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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brevi subspathulata, cellulis alaribus quadratis subpellucidis ornata, in 
laminam ovato-acuminatam tenuiter serrulatam carinatam attenuata, 
nervo angustissimo evanido exarata, e cellulis fabroniaceis reticulata ; 
tlieca parva longius pedunculata entodontoideo-cylindrica rostrata oper- 
culata ; calyptra minuta dimidiata ; annulus latus persistens grande- 
cellulosus; peristomium duplex ; dentes externi 16, angustissimi lineares 
articulati pallide flavocornei, in dentes 4 coaliti latere parum cristati, 
intorni membranam adglutinatam obsolete dentatam sistentes; inflo- 
rescentia monoica. It is named Levierella. 
Gemmae of Aulacomnium.* — Herr C. Muller has studied in detail the 
formation of the gemmae or bulbils in Aulacomnium androgynum. It in 
all cases depends on the production of a two-edged (wedge-shaped) apical 
cell at the end of a leafless pseudopode or gemmophore, but the number 
of segments which are produced from this cell varies. Usually this 
apical cell divides into a large number of segments by walls alternately 
inclined in different directions. But not unfrequently the terminal cell 
first of all divides transversely into two at about half its length, and the 
apical cell then results from the further segmentation of the upper of 
these two cells. The basal cell also always undergoes further division. 
Algae. 
Encrusting and Perforating Algae.* — Prof. R. Chodat enumerates 
the Algae (and Protophyta) which form calcareous deposits on objects 
immersed in water. The Cyanophyceae coming under this head belong 
chiefly to the genera Calothrix and ScMzothrix ; species of the latter 
genus may penetrate calcareous rocks to a depth of 1-2 *5 mm. To 
them is commonly due the caries of pebbles. They also frequently 
attack bivalve shells. Species of Hyella living in consortism with a 
Gongrosira, a Gomontia, or a fungus known as Ostracoblabe , attack the 
shells of marine molluscs. Perforating properties to a very high degree 
are possessed by an alga apparently belonging to the genus Gongrosira , 
which invades the shells of Anodon in the Lake of Geneva. 
Iodine in Algae. :f — According to Herr Eschle, the iodine in Algae 
( Fucus vesiculosus , Laminaria digitata ) is almost entirely in the form of 
an organic compound. 
Melobesiaceae.§ — Herr M. Foslie criticises, on several points, Hey- 
drich’s monograph of the Melobesiaceae. He maintains that there are no 
good generic characters by which LitJiophyllum can be separated from 
Lithothamnion. Sporolithon ptychoides must also be referred to the same 
genus. The alleged “ layers of tetrasporanges ” overgrown by new thallus- 
layers, are, according to the author, abnormal structures caused by the 
attacks of a Rhizopod, which either preys upon existing conceptacles, 
or bores for itself chambers having a close resemblance to con- 
ceptacles. Several also of Heydrich’s species are sunk by Foslie in 
previously described species. 
* Ber. Deutsch. Bot. Gosell., xv. (1897) pp. 279-91 (1 pi.). 
t Arch. Sci. Phys. et Nat., iii. (1897) pp. 512-4. 
+ Zeitschr. Phys. Chem., xxiii. (1897) pp. 30-7. See Journ. Chem. Soc , 1897, 
Abstr., p. 339. 
§ Ber. Deutsch. Bot. Gesell., xv. (1897) pp. 252-60. Cf. this Journal, ante, p. 225. 
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