192 



THE AMERICAN NATURALIST 



[Vol. XL 



List of the Coniferous Remains 



1. Cone scales, allied to Dammara and similar to very small speci- 

 mens of D. microlepis Heer. These are described in this paper on p. 199 

 under the new generic name Protodammara. 



2. Cone scales and leaves of Pinus sp. The scales are relatively 

 small. Several of the leaf specimens showed three in a bundle, enclosed 

 in a sheath. 



3. Leafy twigs of Sequoia reichenbachi (Gein.) Heer, S. heterophylla 

 Vel., Juniperus hypnoides Heer, Widdringtonites reichii (Etts.) Heer, 

 Frenelopsis gracilis Newb., and Brachyphyllum macrocarpum Newb. 



4. Lignite and other fragmentary coniferous remains which could 

 not be generically determined from their external characters. 



5. Amber, occasionally in the interstices of the lignites, but for the 

 most part in the form of small drops or "tears" and irregular fragments. 



Methods Employed in the Critical Examination of the 

 Material 



Maceration and Separatioji of the Gross Material. — In the 

 examination of the finer vegetable debris previously described 

 the following method was employed. Caustic soda or potash 

 in 1 to 3% solution was used with considerable success. After 

 this treatment the fragments of plants were somewhat swollen 

 and separated readily from one another and from the argillaceous 

 matrix. The loosened clay was washed away on a wire gauze 

 tray of not too fine meshwork and the lignitic or carbonaceous 

 fragments were left in a clean and recognizable condition. The 

 fragments in most cases were rather small, especially those of 

 greatest interest, so that the most convenient method of recogni- 

 tion was by means of a dissecting microscope of very low magni- 

 fication. A great many different kinds of coniferous remains 

 were thus separated out and identified from their external appear- 

 ance, as well as many charred specimens of dicotyledonous woods. 

 Of these in general no account will be given at the present time, 

 for attention was restricted to the cone scales similar to those 

 referred by Heer to the genus Dammara, leafy branches belonging 

 to the Brongniartian genus Brachyphyllum, and certain Ar- 

 aucarineous lignites. The chosen material was often in a very 



