ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 51 



elongate without further division while the latter cells undergo several 

 divisions. 10. The walls of the sporogenous mass of cells become 

 gelatinized, and the protoplasts arc potentially free in the gelatinous 

 substance. 11. The spore-mother-cells attain their lobing by a slow 

 amoeboid change of the protoplast, and in this movement vacuoles seem 

 to play an important part. The examination of the living sporogenous 

 tissue of other Jungermanniales verities the occurrence of this phase in 

 them also. 12. Spores with two nuclei have been found, though this is 

 not a usual condition. 



Oxymitra in North America.* — M. A. Howe gives an account of 

 Oxymitra paleacea Bisch. (Tesselina pyramidata Dumort.), an hepatic- 

 known only from the Mediterranean region until it was found in 

 Balansa's Paraguay collection. Recently it has been gathered in Texas ; 

 and some of this sample is under cultivation in the New York Botanic 

 Garden. The Texas plant may, however, prove to be a new species, 

 distinct from the Mediterranean plant in the larger spores, the position 

 of the antheridial inflorescence, and the structure of the stomata. The 

 author discusses, the tangled nomenclature of the generic and specific 

 names. 



The same author f publishes further notes on the Texan Oxymitra 

 (Tessellina), a supplement to his paper on Oxymitra paleacea or Tessellina 

 pyramidata.% The latter is a Mediterranean species, and is dioicous, 

 but the Texan plant on being cultivated is found to be synoicous. The 

 author therefore gives it the name Oxymitra androyyna sp. n., and 

 describes its structure. 



Marsupella.§ — ■ T. Husnot publishes notes on some species of 

 Marsupella. 1. The cell-structure of 31. commutata has been figured by 

 the two experts Massalongo and K. Midler with very discordant results ; 

 the one showing ovoid, and the other quadrate cells. The cells are in 

 reality hexagonal, as figured by Husnot, and when otherwise figured by 

 other authors it is because the outline is taken not from the wall, but 

 from the cytoplasm which lines it. The cells do not differ from those 

 of At. FuncJcii, nor do the outline of the leaves, nor the shape of the 

 lobes afford any trustworthy ground for distinguishing these two species. 

 Husnot regards 31. commutata and 31 . badensis as no more than forms 

 of 31. FiiHckii. 2. 31. ustulata and 31. Sprucei are distinguished by the 

 larger size of the cells in the latter species — a character very variable on 

 the same plant. Also the acute or obtuse lobes of the involucral leaves 

 is no constant character. These two species are not distinct. 



Bryum tophaceum.|| -L. Trabut discusses the identity of Bryum 

 tophaceum D. R. & Mont., a nmss gathered at Tiaret in Algiers more 

 than sixtv years ago, but sterile and almost unknown to brvolouisi-. 



* Brvologist, xvii. (1914) pp. 72-5 (1 fig.), 

 t Brvologist, xvii. (1914) pp. 92-4. 

 t Brvologist, xvii. (1914) pp. 72-5. 

 § Rev. Brvolog., xl. (1913) pp. 76-7. 

 Rev. Bryolog., xl. (1913) pp. 45-6. 



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