278 Sinnott and Bartlett — Coniferous Woods. 



(These three nominal species of Onychiopsis are found 

 in the Arundel and Potapsco formations, as well as in the 

 Patuxent.) 

 Cycadophyta 



Dioonites Buchianns (Ettings.) Born. 



(A widespread type, but in the Potomac known with cer- 

 tainty only from the Patuxent. A very abundant fossil at 

 the Central High School site. Fine and characteristic 

 specimens were obtained ; the first unquestionable material 

 from north of the Potomac River.) 

 Zamites tenuinervis Fontaine 

 Podozamites lanceolatus (L. & H.) F. Braun 

 Podozamites acutifolius Fontaine 

 Podozamites distantinervis Fontaine 



(Numerous single leaflets, for the most part fragmen- 

 tary, but obviously representing several different forms, 

 are somewhat doubtfully identified with these nominal 

 species of Zamites and Podozamites.) 

 Nilsonia densinervis (Fontaine) Berry 



(A single small but well-preserved fragment. Known 

 from the Patuxent and Arundel formations.) 

 Coniferse 



Nageiopsis zamioides Fontaine 

 Nageiopsis angustifolia Fontaine 



(Numerous leaves in an unsatisfactory state of preserva- 

 tion, none of them attached to twigs. Both species are 

 known from all three formations of the Potomac group.) 

 Cephalotaxopsis magnifolia Fontaine 



(Very doubtfully identified from one fragmentary leaf, 

 which differs from all the other coniferous remains in hav- 

 ing a very broad mid-vein.) 

 Brachyphyllum erassicaide Fontaine 



(Scanty but satisfactory specimens.) 

 Arthrotaxopsis grandis Fontaine 



(Both cones and foliage which, however, are not 

 attached. The most abundant fossil of the beds. Twigs 

 very slender, and indistinguishable from forms which have 

 been called Widdringtonites ramosus (Fontaine) Berry. 

 Widdringtonites is characterized by four-valved cones. 

 From the manner of occurrence of our fossil, it seems 

 highly improbable that the many-scaled cones which we 

 have associated with it belong to any other form. Per- 

 haps it is worth while to suggest that all of the so-called 

 Widdringtonites of the Potomac is in reality Arthrotaxop- 

 sis.) 

 Sphenolejyis Kurriana (Dunker) Schenk 



(Next to Arthrotaxopsis and Nageiopsis the most abund- 

 ant conifer.) 

 Sequoia ambigua Heer 



(Scanty impressions, without cones.) 



