548 Bryophyten. — Floristik, Geographie, Systematik etc. 
and illustrated. (The Bryologist. XI. p. 1—3. plate 1. January, 
1908.) 
Lophozia Runzeana (Hüben.) Evans, L. Muelleri (Nees) Dumort 
and L. porphyvoleuca (Nees) Schiffn. are illustrated. The descriptions 
are excerpted from articles published by Dr. Evans in Rhodora 
1905 and 1906. Maxon. 
Brown, 3., Alpine flora of the Canadian Rocky Mountains. 
Illustrated with water-colour drawings and photographs 
by Mrs. Charles Schaffer. (New York & London. G. P. Put- 
nam's Sons. 1907. 12°. XXXIX, 353 pp. 80 pl.) 
An attractive handbook of the more striking plants between 
Banff and Glacier, comprising the distinct floral elements of the 
moist Selkirks and the dry Rockies. Such less attractive and 
more difflcult groups as grasses, sedges and willows are omitted. 
A glossary and general analvtical kejr precede the popularly-cast 
descriptive account of the plants, which are adequately characterized 
and unusually well pictured in large part. Sequence and nomencla- 
ture are modern. Trelease. 
Chase, A„ Notes on genera of Paniceae II. (Proc. Biol. Soc. 
Washington. XXI. p. 1—9. f. 1—3. Jan. 23. 1908.) 
Continuation of a series begun in the same journal in December 
1906. The present part deals with Hymenachne and Sacciolepis, and 
contains the following new names: Hymenachne auriculata (Panicum 
anriculatum Trin.), H. palustris (P. palustve Trin.), Sacciolepis myu- 
ros ( P . myuros Lam.), S. vilvoides ( P. vilvoides Trin.), S. strumosa 
(P. strumosum Presl.), S. indica (.Aira indica L.), and S. curvata (P. 
curvatum L.) Trelease. 
Chrysler, M. A., The structure and relationships of the 
Potamogetonaceae and allied families. (Botan. Gazette XLIV. 
p. 161 — 188. Pis. 14-18. Sept. 1907.) 
The structure, especially vascular, of thirteen species of Pota- 
mogeton, and one each of Ruppia, Zostera, Phyllospadix , Cymodocea, 
and Zannichellia have been studied from the phylogenetic standpoint. 
The results of his investigations, in connection with certain well 
known morphological features lead the author to conclude that Po- 
tamogeton is the most primitive of all, and that it possesses several 
characters inherited from possible dicotyledon ancestors. Among the 
anatomical grounds upon which these conclusions are based, the 
more notable urged are, that the xylem is well-developed in the 
nodes, floral axis, and young stem of many species of Potamogeton, 
and that the floral axis is more plainly occupied by a circle of 
bundles than in any other genus except Triglochin. 
The remaining genera of the Potamogetonaceae are found to be 
more highly specialized, the specialization having been brought 
about in the main by reduction to effect a more perfect adaptation 
to aquatic conditions. Two lines of possible descent are outlined, 
one comprising Zostera, Cymodocea and Halodide, and the other 
Ruppia and Zannichellia, to the latter of which Naias may be 
related. Probable reduction in the Naiadaceae has been carried to 
such an extreme, however, that the affinities of this family are 
doubtful. 
