DESCRIPTION OF TUE srECIES. 213 



times ribbon-shaped, incised at tlie tips or entire, inserted on sliort branches; 

 nerve-bnndle issuing from the base of the leaf and repeatedly forking-. 



Tiiis description, which is that given by Schimper on page 2()1 of the 

 second volume of Zittel's Handbook, applies to only one of the forms of 

 the Potomac. The essential point is the insei'tion of the leaves in tufts on 

 the summit of short branches which form annually. Tliis is a very 

 different arrangement of the leaves from that in Baieropsis, where they are 

 all in one plane, arranged pinnatelv on the sides and at the tips of leafy 

 twigs. 



Baikra koliosa, sp. nov. 



Plate XCIV, FiK. 13. 



Leaves numerous, grouj)ed in bundles or tufts at the summit of short, 

 stout, annual growths, having their basal portions long, slender, and grad- 

 ually narrowing into a pedicel ; their upper portions dichotomously divided 

 into a small number of strap-shaped lacinije, the ultimate ones being a little 

 over 1""" wide; nerves slender, forking at long intervals, with branches 

 pnrallel. 



Locality : Fishing hut above Dutch Gap Canal. 



This plant, evidently a true Baiera, is very rare, the specimens, few in 

 number, being, with the exception of the one figured, found in small frag- 

 ments. The leaves at the summit of the short twigs seem to have been 

 very numerous and more slender than in the Jurassic Baieras. 



FRENELOPSIS, Schenk. 



Trees or shrubs ; stems seen in thickness up to 5"™ and more ; sterna 

 and branches cylindrical, jointed, branches alternate or whorled, radiating 

 from the same zone on the principal stems and curving upwards ; epider- 

 mis dense and durable, cortical tissue thick, and apparently succulent ; 

 leaves on the joints very short, varying somewhat in shajje, normally more 

 or less triangular in form, acute, close appressed, not decurrent, minute and 

 scale-like, one to three in number, alternating in position on the successive 

 joints ; epidermis marked with minute tubercles arranged in rows, which 

 to the unaided eye appear as line striae running longitudinally on the stem 



