1922] CURRENT LITERATURE 229 
Calamites.—Impressions. of casts of the external features of Calamites 
plants. In all four of the large monographs now available on the Calamites, 
by Stur, Weiss, Kinston, and especially JonGMANS, by far the greater number 
of the figures relate to the pith casts. As a rule, examples of both medullary 
casts and impressions showing the true external features of the stem are mixed 
together in confusion, and are all referred to a common genus, Calamites. 
Neither from the generic nor the specific names employed can one distinguish 
whether one is dealing with pith casts or with the rarer external surfaces of 
these stems. It is hardly necessary, however, to point out that incrustations 
of the external features of the stems of these plants are of an entirely different 
morphological nature from the medullary casts. For this reason ARBER ha 
Proposed in 10916 : new form genus, Calamophioios, for the external stem 
impressions, with the exception of the very distinct type of Dictyocalamites 
which had been atone already in 1912. 
and LAWFIELD® intend to establish a number of species of these 
two new types, and they suggest that the same specific name may be used for 
both types of preservations, the internal and external ones. They avoided 
adopting new specific names for the types of Calamophloios, therefore, as 
compared with the pith casts. The authors also succeeded in carrying out 
a correlation of a number of external surfaces and pith casts of Calamites.— 
A. C. Not 
Pliocene flora of Varennes.—The Pliocene flora of Varennes is the subject 
of a monograph by De La Vautx and Marty,** which is divided into the 
following sections: (1) geology of the fossiliferous beds of Varennes, (2) a critical 
study of the fossil plants of Varennes, (3) a description of new species discovered 
in the deposits of Varennes, (4) paleontological, stratigraphical, botanical, 
i chapter o i 
Varennes is added. Of the forty-seven genera which are described in 
— siseaah of Varennes, aa — sae to twenty-three Satie ae 
Fourteen new species were established. 
Ecologically, the flora oe Gansu indicates a temperate climate, because 
of the thirty-seven definite species found at Varennes, thirty-four belong to 
the temperate zone. This flora also contains more continental than insular 
species. Almost all the species which tort the flora of Varennes, - hoses 
nearest living relatives, inhabit at p 
» ARBER, E. A. NEWELL, and LAWFIELD, F. W., On the external morphology of 
the stems of Calamites, with a revision of the British species of Calamo 
Dictyocalamites of Upper Carboniferous age. Jour. Linn. Soc. 44:507-530. pls. 23-25. 
1920, 
* De La Vautx, Rotanp, and Marty, Pierre, Nouvelles recherches sur la 
flore fossile des environs de Varennes. Rev. Gen. Bot. 32:282-300; 327-336; 351- 
68. 1920 
