298 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



occurrences of the latter have also been found to belong to Sequoia 

 ambigua Heer. 



The present is another of the several species which may be com- 

 pared with the foliage from the Lower Cretaceous of Greenland which 

 Professor Heer referred to Cyparissidium. 



Occurrence. — Patuxent formation: Roadside near Potomac Run, 

 Telegraph station (Lorton),Trents Reach, Dutch Gap, Cockpit Point, 

 Virginia; Springfield (?), Maryland. Arundel formation: Lang- 

 don, District of Columbia, Bay View, Tip Top (?), Maryland. 



Collections. — U. S. National Museum. 



THE GENUS CEPHALOTAXOPSIS OF FONTAINE. 1 



The utility of a new generic designation for the Potomac forms 

 included in this genus is not altogether obvious with Ce phalotaxiles 

 and Taxites already in use, but as it is in the literature and differen- 

 tiates an abundant type, which is at least specifically distinct from the 

 species usually referred to the two genera just mentioned, it is retained 

 in the present publication. It may be characterized as follows: 



Description. — Much branched, limbs stout, apparently in a single 

 plane, although it is impossible to determine to what extent this is 

 due to pressure during fossilization. Leaves flat, linear-lanceolate, 

 coriaceous and persistent, rather variable in size, mucronate tipped; 

 base slightly decurrent and twisted; midrib broad and flat, bordered 

 on either side below by a stomatal groove. The leaves are distichous 

 in habit, but the phyllotaxy was undoubtedly spiral, as it is in so 

 many other gymnosperms with the distichous habit, and is attested 

 by the twisted leaf bases. No fruits have been found upon any of the 

 abundant foliage specimens, although certain associated species of 

 Carpolithus 2 are mentioned by Professor Fontaine as the probable 

 fruits of this genus, which are assumed to have been drupe-like with a 

 bony seed after the manner of the existing species of Podocarpus and 

 Cephalotaxus. This may well have been the case. The fact that no 

 fruiting specimens occur in the abundant sterile material lends some 

 support to this interpretation, since such fruits would stand far less 

 chance of successful transportation by water and subsequent fossiliza- 

 tion than would the woody buoyant cones of the majority of the 

 conifers. 



With the genus Tumion probably present in the Virginia Potomac 

 and with Nageiopsis representing the subfamily Podocarpese, the 

 family Taxaceae is abundantly represented in the Lower Cretaceous, 

 and when the individual abundance is considered rather than the 

 specific differentiation, it must be admitted that this family furnishes 

 an important element in the Potomac flora. 



i Fontaine, Monogr. U. S. Geol. Surv., vol. 15, 1890, p. 235. 

 2 C.fasciculatus, C. mucronatus, C. sessilis, C. ternatus. 



