MARYLAND GEOLOGICAL SURVEY 805 



type. He characterized the genus in the following terms : " Folia numer- 

 osa in ramulo abbreviato, caduco fasciculata, subulata, rigida, dichotoma, 

 squamis compluribus persistentibus circumdata. Flores feminei racemosi. 

 Fructus pedunclo brevi insidens, nuculis duabus valde approximatis." 



The genus is discussed at length by Heer, who considers that the asso- 

 ciated small seeds represent the same plant which is therefore placed 

 among the Gymnospermce and referred to the Ginkgoales. In this refer- 

 ence most later students concur (vide Schenk in Zittel, Palaophytologie, 

 p. 267, 1890; Seward, Jurassic Flora, pt. I, p. 276, 1900), although identi- 

 cal remains have constituted the genera Jeanpaulia of linger, 1 Sdero- 

 phyllina of Heer, 2 and Solenites of Lindley and Hutton. 3 These remains 

 in whole or in part have been variously referred to the Algce (Lindley and 

 Hutton), to the Rhizocarpacece (F. Braun, linger, Brongniart), to the 

 Isoetacece (linger, Brongniart, Zigno, Schimper), and to the Filicales 

 proper (Shenk, Schimper, etc.). 



The genus Czelcanowskia, which is intimately related to Trichopitys 

 Saporta and Baiera F. Braun, is distinguished from both chiefly by the 

 less divided, or undivided, needle-like leaves. It is confined to the north- 

 ern hemisphere, appearing in the Rhsetic of Scandinavia (C. longissima 

 Nathorst) , and becoming differentiated and widespread in Middle Jurassic 

 times (C. Jieerii ISTathorst, C. setacea Heer, C. palmatisecta Heer, (7. rigida 

 Heer, and C. viminea (Phillips) Berry 4 It is represented in the Lower 

 Cretaceous by (7. dichotoma Heer of the Arctic regions and C. nervosa 

 Heer of western Europe. The latter survives into the Upper Cretaceous, 

 and a single species, C. capittaris Newberry, is present in the early Upper 

 Cretaceous of America. All these forms are very much alike megascopi- 

 cally. 



The remains are often common but are usually poorly preserved and 

 resemble masses of long slender needle-leaves like those of Pinus, and this 



1 Unger, Gen. et Sp., p. 224, 1850. 



2 Heer, Urwelt der Schweiz, p. 55, 1865. 



3 Lindley and Hutton, Foss. Fl. Gt. Britain, vol. ii, pi. cxxi, 1834. 



4 This is the correct name for the form commonly called C. Murrayana (L. 

 and H.), since Phillips' name antedates that of Lindley and Hutton by five 

 years. 



