ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 583 



commou centre. He differs from Limpriclit by taking the view that 

 AmblijstegiumfiJicinuni and A. curvimulehelongto Hygroamblystegium ; 

 and he holds that H. fallax and its allies form a strongly differentiated 

 aquatic branch of this genus. He strongly suspects the accuracy of 

 Renauld's contention that ffz/pnumfiUcimiin [^converted into ^^ H. fallax 

 ( Vallis Clausce) " in a swift stream in the Pyrenees. Parallel forms 

 they perhaps may be, but not a true conversion from the one species to 

 the other. He also discusses at some length the value of species, sub- 

 species, genus and " gesamtgattung," and expresses his own views on 

 the subject, and points out the influence of the personal factor in defining 

 the limits of a species. . He maintains that everything should be 

 described without exception, but that only those forms should be named 

 which are capable of being recognised with certainty from a description 

 or plate, or of which the author has a sufficient stock of material to 

 supply samples to everyone interested. 



European Hepaticse.* — K. Miiller, of Bromberg, publishes the fourth 

 part of his monograph of the European hepatics. He finishes the 

 Eicciacete, giving descriptions of 14 more species of Riccia and one 

 each of Ricciocarpus and Tessellina. Proceeding to consider the Mar- 

 chantiaceae, he shows in a diagram the probable course of descent of 

 the genera. In contrast to the Ricciese, the Marchantiacefe exhibit 

 great variety in the anatomy of the thallus and the composition of the 

 two sorts of inflorescences, thus affording far more characters for 

 systematic determination. And the author gives a useful list of points 

 to be noted in the examination of unknown specimens. He appends an 

 artificial key to the genera, based on easily observed and permanent 

 characters, such as structure of thallus, form of stoma, ventral scales, etc. 

 Another key is strictly systematic, and shows the principles upon which 

 the genera are grouped. The species of the following are described — 

 Corsinia, Targionia, Gyathodium, Clevea (2), Sauteria, Feltolepis, Plagio- 

 chasma (2), Rehoulia. 



New British Hepaticse.t — S. M. Macvicar publishes some critical 

 notes on the following British hepatics : — Lophozia Baueriania Schiffn., 

 Lophocolea alata Mitt., Scapaiiia obliqua Schiffn., Modotheca rivularis 

 Nees. He agrees with Schiffner and Arnell in regarding Lophozia 

 Baueriana as a true species, and he points out the most useful characters 

 for distinguishing it from L. lycopodioides and L. Floerku ; and he 

 sketches out the distribution of these three species in Britain. As to 

 Lophocolea alata, published by Larter after Mitten's death, and founded 

 on a single small specimen, Macvicar has examined several additional 

 specimens from the original locality in North Devon and elsewhere, 

 and finds that they vary so much in the specific characters emphasised 

 by Mitten, that it seems better to regard the plant as a sub-species of 

 L. cuspklata, which is not so common in England but more common in 

 Scotland. He also records the occurrence of Scapania obliqua in this 

 country, shows how it is distinguished from S. undulata and 8. uliginosa, 

 and gives its British distribution. Finally, he gives notes on two 

 varieties of Madotheca rivularis which are new to Britain. 



* Rabenhorst's Kryptogamen-Flora, vi. lief. 4 (1907) pp. 193-256 (figs.). 

 t Journ. of Bot., xlv. (1907) pp. 258-63 



