ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 481 



the antlierozoid is mature. 7. During certain stages another con- 

 spicuous cytoplasmic body, called the percnosome, because of its staining 

 properties, seems to be regularly present. It is probably identical with 

 a smaller granule which is generally recognizable both at an earlier and 

 at a later period. This smaller body sometimes lies in a rather large 

 vacuole. 8. At this time the androcyte is approximately spherical, but 

 becomes lenticular as the cytoplasm decreases. Part of the cytoplasm 

 with the limosphere remains included within the curve of the posterior 

 end of the mature antherozoid. 9. The walls that separate the andro- 

 cytes become dissolved. The mature antherozoid lies in a vesicle which, 

 as the contents ooze out of the antheridium, appears to be bounded by a 

 distinct outline, though in fixed material no trace of such a membrane 

 is to be found at this late stage. The separate vesicles are imbedded in a 

 viscous substance which probably is derived from the material of the 

 broken-down walls. 



Illustrated Key to Ditrichacese.* — T. C. Frye publishes an illus- 

 trated key to the Ditrichacete of America west of the Rocky Mountains 

 between Mexico and the Arctic Ocean. The number of species con- 

 cerned is sixteen, half of which belong to Ditrichum. The other 

 five genera are Pleuridium, Swartzia, Trichodon, Geratodon, Saelania. 

 Figures are given of the leaf-structure of each species and of the peristome 

 characters. The keys provide for the determination of both genus and 

 species, whether fertile or sterile. 



Tasmanian Hepaticae.t — L. Rodway publishes a systematic account 

 of the Tasmanian Hepaticae, which, issued separately, provides a hand- 

 book to this group of plants. Descriptions of all the orders, families, 

 genera and species are given ; and, by the insertion of keys to the genera 

 and species, the determination of specimens is much facilitated. The 

 number of species approaches 300, which means a very rich flora. 



New Tasmanian Bryophyta.| — L. Rodway describes some additions 

 to the Bryophyte flora of Tasmania, namely, three mosses and nine 

 Hepaticffi. Ten of these are new to science, as also probably is the moss 

 referred to Blindla acuta, for it differs from the type in its leaf-structure. 

 The nine new Hepaticae represent eight genera. 



Philippine Mosses. — R. S. Williams publishes a list of 240 mosses 

 collected by him in 1903-5 in the Philippine Islands, Luzon and 

 Mindanao. These fall into 118 genera. The author gives descriptions 

 of 27 new species and three new genera, the structure of some of which 



. is figured in the plates. The new genera are Rhahdoweisiella, Pseudo- 



pohlia, and Stereodontop)sis. 



* Bryologist, xx. (1917) pp. 49-60 (16 figs.). 



t Proc. Roy. Soc. Tasmania for 1916 (Hobart, 1917) pp. 51-143. 

 X Proc. Roy. Soc. Tasmania for 1916 (Hobart, 1917) pp. 44-7. 

 § Bull. New York Bot. Gard., viii. (1917) pp. 331-78 (4 pis.). 



Oct. 17tK 1917 2 K 



