274 FOSSIL PLANTS FROM TEXAS — rONTAINE. 



joiiilcd I'onii is sliown in PI. \li, Fi^-. L*. The most common form, 

 liowcver, shows iiiteniodos or joints a\t'i;igiiiii nhont 15 millinieters 

 in lenurli, except towards tUv l»ase ol' tlu' ultimate twij^s, where, near 

 their attachment to the penultimate twigs, they uniformly are much 

 sliortened, heiiijj 7 or 8 millimeters or less in lenjith. These forms, 

 which we may rejiard as the normal ones, have an average width for 

 the joints of about millimeters. This normal form is represented by 

 V\. XLT, Fig. 3. Othei' specimen^, however, show great irregularity, the 

 joints varying in length according to no rule, normal joints and short 

 ones being intermixed. This is seen in PI. XL, Fig. 1, especially in the 

 right lower ultimate twig. The dimensions of the ultimate and penul- 

 timate twigs do not vary much. The ultimate twigs must, in some 

 cases, have attained a considerable length, f(n* fragments were seen 16 

 centimeters long, Avhich did not have the ends i)reserved and did not 

 show any marked diminution in diameter. The largest twig seen is a 

 mere fragment, and is shown in PI. xli. Fig. 1. This shows the largest 

 woody axis, for this axis appears to conform in size to the dimensions 

 of the twig. The ultimate twigs seem to have been in their attach- 

 ment to the ultimate ones rather remote and scattered around them. 

 Some short twigs Mere found which seem to have been undeveloped 

 ultimate twigs. One of these is represented in PI. xl. Fig. 2. These 

 forms show abbreviated nodes Mhicli strikingly r<'semble tin* leaves at 

 the summit of the cone-bearing twigs of P<i</i()])Jii/lhiiii dulilum. 



The leaves are almost always undeveloi)ed. The summits of the 

 joints which should show the leaves, if they were present, abuost 

 always appear as a lin«>, of constriction which has various attitudes. 

 It may run at right angles to the axis of the twig, or be inclined to it, 

 in both cases being nearly straight. In other cases, and these are 

 c(nnnu)n, the constriction may be convex upwards or concave down- 

 ward. These succeed one another in such order as to indicate that the 

 ends of the joints bear undevelo])cd teeth or leaves of triangular type. 

 In a very few cases there are very slightly developed teeth or leaves, 

 which have the form of very broad, low triangles. This is shown in the 

 form given in PI. xli. Fig. 3, where the right-hand lower ultimate twig, 

 on the summit of the third joint from the attachment, shows a leaf of 

 this kind. 



The almost universal absence of developed leaves is one of the most 

 important i)oints of difterence between this plant and F. parcentniosn, 

 for in this latter visible leaves are quite ct)nnn()n, and of the character 

 of those occurring with extreme variety in the Texas i)lant. It should 

 be noted, however, that in the Potimiac fossil a number of specimens 

 show only tlie lines of constrictiini, as in the case of F. rarians. The 

 leaves when present api)ear to be one at the summit of each joint. 

 While the Texas plant is most i)robably si)eci(ically distinct from F. 

 ]}((rcero)n(hS((, it is very near to it, being nearer than to F. Ilohcuruf/cri 

 JSchenk, of the Urgouian of Europe. This latter seems to be interme- 



