234 UNITED STATES GEOLOGICAL SURVEY— TERTIAEY FLORA. 



in all the stages from tlie Upper Eocene to the Quaternary. None, however, 

 have been described until now from the Lower Eocene floras, Sezanne, Gelin- 

 dcn ; none also from the Cretaceous. Now we have in the North American 

 Cretaceous flora already two species of Andromedd, while from that of the 

 whole Tertiary we know only two: A. Grayana., Hcer, recorded by the 

 author from Barrard Iidet, from Alaska, and here below from the Lignitic 

 of the West, with one single leaf referred to Vaccinium reticulatum, whose 

 identity is not even positively ascertained. I have seen none in the Pliocene 

 plants of Calilornia, and none either in the Miocene of Oregon. 



In considering the cause of this peculiar distribution of the Ericacece in 

 the geological floras of this country, we might tind some kind of explanation 

 in the fact, already mentioned by Schimper, that a large number of the fossil 

 species of this order are of doubtful attribution. The absence of plants 

 of the same order in the Tertiary formation of this continent, when com- 

 pared with the large number of species living at our time, might also be 

 accounted for by their present habitat. They mostly live now in deep woods, 

 especially in sandy soil, along the rocky banks of the hilly torrents, on the 

 top of the mountains, and on the surface of the j^eat-bogs. Few are found 

 on the borders of marshy ponds oi' of hollow lakes. Gaylussacia resinosa, 

 Vaccinicum coryiubosum, Andromeda ligustrina, and Clethra Alnifolia are 

 exceptions ; but their leaves are not of a hard consistence, and seem likely 

 to be easily destroyed by maceration. The same remark as the one applied 

 already concerning our limited acquaintance with the fossil floras of this 

 continent and the wide range of probabilities for future discoveries is equally 

 appropriate to this case. Moreover, as the leaves of the Ericacece. are mostly 

 small, they are not likely to come first to view in the explorations. 



ANDROMEDA, Linn. 

 Andromeda Orayana, Heer. 



Plate XL, Fig. 4. 



Andromeda Grayatia, Hcer, Fl. Foss. Alask., p. 34, pi. viii, fig. 5; Vancouver ii. Brit. Colum. Foss. Pfl., 



p. 7, pi. 1, figs. 7-9. — Lcsijx., Aumial Report, 1871, p. 298. 

 Andromeda reticulata?, Lescix., Aunual Report, 1871, p. 298. 



Leaves subcoriaceous, lanceolate, narrowed in a curve to the petiole, very entire; lateral nervea 

 at au acute angle of divergence, parallel, camptodrome. 



From numerous specimens which I originally referred to this species, 

 the one figured is the more complete. It is like fig. 9 of Heer, with the base 

 more distinctly rounded in narrowing. Other specimens of the same locality 



