ZOOLOGY AND BOTANY, MICROSCOPY. ETC. IS^ 



ring of cells with strongly thickened but not sclerotic walls, and some- 

 times the form of the central cylinder, are extremely useful characters. 

 In the petiole the number of bundles, and especially the form of the 

 xylem in them, the presence or absence of sclerotic strands, or of a 

 sclerotic sheath, constitute characters of first importance for determin- 

 ing genera, and sometimes species. The structure of the stem is cha- 

 racteristic only in exceptional cases ; as a rule, the bundles form an 

 inextricable network. In some cases these anatomical characters agree 

 with the morphological facts, as, for instance, in Polypodiimi, Adiantum,. 

 Grammitis, Osmunda. On the other hand, these characters indicate 

 that Scolopendrium should be associated in one and the same tribe with 

 Asphjiium and Ceteracli, and that Lomaria and Blechnum should not 

 only be put into one and the same tribe, but even united into one genus. 

 Again, the indication is that Athyrium should be split off from Asple- 

 nium, and Phef/opten's from Polypodium, and PterkUum from Pteris. 

 Two well marked sections are indicated in Notochlcena. The species 

 of Aspidium, Nephrodium, Polystichum, should be arranged in two 

 groups ; in one the root has a sclerotic sheath, and the petiole con- 

 tains several bundles, of which the two principle ones have the xylem 

 shaped like a " cornu " ; in the other the root has no such sheath, and 

 the petiole contains two bundles only, with the xylem shaped like a 

 " hippocampus." The first is called Aspidium by the author, the second 

 is Nephrodium. Again, some species are more readily distinguished from 

 one another by the anatomy of root and petiole than by morphological 

 difference. Finally, the author provides an illustrated key to the ana- 

 tomical differences of the species of ferns proper to France. 



Bryophyta. 

 (By a. Gepp.) 



British Hepatlcse.* — S. M. Macvicar publishes critical notes on- 

 new and rare British Hepaticse. (1) Riccia Huebeneriana, Linden, var.. 

 pseudo-Frostii Schiffn. was found at Crowborough and Horsted Keynes, 

 Sussex, by W. E. Nicholson. According to Schiffner, it is worthy of 

 specific rank. Owing to its large air-cavities, it might be confused 

 with R. crystallina ; but the latter is always green, and never violet. 

 (2) Lophozia badensis Schiffner has been much confused with L. turbinata 

 Steph., and to some extent with small forms of L. Muelleri. This- 

 confusion has been cleared up by Schiffner. Macvicar cites stations for 

 L. badensis in Yorkshire and Scotland, and describes the salient points 

 of all three species, and shows how the Jungermannia acuta of 

 Lindenberg — a mixed species — has added to the confusion. (3) Priono- 

 lobus striatulus Schiffn. has been gathered in Lanarkshire by Macvicar, 

 where it occurs at an altitude of r.)00 ft., growing on masses of 

 decaying Sphagnum, associated with Vaccinium MyrtiUus, Empetrum, 

 and Polytrichum. It has been found in Scandinavia and France. In 

 the latter country it has been mistaken for Cephalozia elachista, which, 

 according to Douin, has not been found in France. Lately (7. elachista 

 has been found in Sussex by Nicholson, the only previous British station 



♦ Journ. of Bot., xlv. (1907) pp. 63-6. 



