WARD.] DISCUSSION OF THE TABLE. 531 



changed, so far as can be judged by the organs (chiefly appendicular) 

 that have been found in the fossil state. The two species of hazel, and 

 also the sensitive fern from the Fort Union deposits regarded by Dr. 

 Newberry as identical with the living forms, must be specifically so re- 

 ferred until fruits or other parts are found to show the contrary. The 

 bald-cypress of the Laramie swamps seems not to have been specifi- 

 cally distinct from that of the swamps of the Southern States, and, as I 

 shall soon show, forms of the Ginkgo tree occur not only in the Fort 

 Union beds, but in the lower Laramie beds at Point of Eocks, Wyoming 

 Territory, which differ inappreciably except in size of leaf from the living 

 species. 



To the strong evidence against the Eocene age of the Laramie group 

 afforded by the persistence of so many of its types into periods much 

 more recent than Eocene may perhaps be added evidence equally ad- 

 vei'se but of the opposite nature. A few Laramie forms occur in Cre- 

 taceous strata. Sequoia Langsdorfii is found, as we have already seen, 

 in the Cretaceous of both British Columbia and Greenland, and Ginkgo 

 polymorplia in the former of these localities. Cinnamomum Scheuchzeri 

 occurs in the Dakota group of Western Kansas as well as at Fort Ellis. 

 Sir William Dawsou detects in strata regarded as Laramie by Prof. G. 

 M. Dawson, of the Geological Survey of Canada, a form which he con- 

 siders to be allied to Quercus antiqiia, Newby., from Eio Dolores, Utah, 

 in strata positively declared to be the equivalent of the Dakota group. 



Besides these cases there are several in which the same species oc- 

 curs in the Eocene and the Cretaceous, though wanting in the Lara- 

 mie. Cinnamomum Sczannense, of the Paleocene of Sezanne and Gelin- 

 den, was found by Heer, not only in the upper Cretaceous of Patoot, but 

 in the Cenomanian of Atane, in Greenland. Myrtophyllum cryptoneuron 

 is common to the Paleocene of Geliuden and the Seuonian of West- 

 phalia, and the same is true of Deiralquea Gelindensis. Sterculia vari- 

 abilis is another case of a Suzanne species occurring in the upper Creta- 

 ceous of Greenland, and Heer rediscovers in this same Senonian bed the 

 Eocene plant, Sapotacites reticulatus, which he originally described from 

 Skopau in the SachsThiiringeu lignite beds. 



Before commencing this discussion from the iJoint of view of specific 

 relationship it was remarked that it would differ from that just closed, 

 where the subject was treated from the point of view of generic rela- 

 tionship, in dealing with geological, or time relations, rather than with 

 geographical, or space relations. But we have already seen that the 

 latter considerations could not be kept wholly out of view, and we shall 

 now see that they really form a very important part of this mode of treat- 

 ment, if it is to be made at all complete. Of the seven species confined 

 to the Laramie and Eocene it was seen that four were also confined to 

 this continent. This anomaly arose from having placed the Mississippi 

 Tertiary in the last column of Eocene localities. But the Green Eiver 

 group, which is by most geologists regarded as the Eocene of Western 



