MUSCOLOGIA GALLICA. 157 



The nomenclature adopted is that which prevails in most 

 bryological households, viz., that of Schimper's Si/nnp!<is, edition ii., 

 with a few alterations, e. g. Plcujiohnjum in place of the preoccupied 

 Zieria. Deviations from the customary systematic arranfjement 

 are to be noted in case of Arclddinin and Voitia. The first of these, 

 so anomalous in the structure of its sporophyte, is, on account of 

 its vegetative similarity, placed next to Pleurulinm. Voitia, on the 

 other hand, though resembling the SpIachiacecB in vegetative 

 structure, is placed next to Bruchia ; and this latter, approaching 

 Trematodon in the form of its sporophyte, is classed with the 

 cleistocarpous genera Flenridimn and Phascuiii, on account of its 

 indehiscent capsule and vegetative similarity. 



The Sphagnacecc are nowadays regarded as a separate branch of 

 the MuscinecB, the study of which is usually relegated to the well- 

 Imown specialist. Dr. Warnstorf. They are omitted from the present 

 work. On the other hand, two very difficult groups — the genus 

 Ortlwtrichum and the Harpidium section of the genus Hypnum^ 

 are most elaborately treated by eminent specialists. M. Venturi 

 has made himself responsible for Orthotriclnim, and has produced a 

 most exhaustive monograph of all the species and varieties that 

 occur in Europe, and has included some that are found in outlying 

 regions— in all, forty-two species ; and has drawn the excellent 

 figures that illustrate his minute and exact descriptions. A new 

 species — O. caucasicum Vent. — will be found on p. 176. For a 

 proper study of the capsules of dried specimens, M. Venturi says 

 that it is indispensable to soak them in water for half a day. 

 I venture to think, however, that this time could be considerably 

 reduced by the application of gentle warmth. At any rate, it is 

 sufficient to soak the capsules of most mosses for half an hour in 

 tepid water on a steam radiator, and even the leaves of Dissodon 

 and the thallus of such hepatics as Cijathoditim soon recover under 

 this treatment. 



The subgenus Harpidium has been contributed by M. Renauld, 

 who has based his text and drawings upon original types. The 

 difficulty presented by the group is due to the infinite variability of 

 its members, owing to local conditions, and the absence of fixed 

 characters by which they might be classed. In order to avoid 

 breaking natural affinities, M. Renauld has preferred to place in 

 relief the most widely diffused forms, and to group around and 

 between them the innumerable intermediate forms. Thus he has 

 maintained six species of the first rank, four of the second rank, 

 and varieties and forms too many to count. All the forms of 

 France and of neighbouring countries, and some from N. America, 

 are included. Every one who has occasion to investigate this 

 troublesome group will find M. Renauld's descriptions and plates to 

 be a sine qua non. 



There are several other points upon which I should have liked 

 to touch, but, with a view to economising the space and time at my 

 disposal, I must limit myself to a few brief references. Under 

 Fvntinalia the seven or more species of most authors are reduced to 

 three. The species of PJiynchosteyium are transferred to Eurhyuchiwn. 



