170 DK KOBERT K1DSTON ON THE 



Remarks. — Some place Dicranophyllum in the Ginlcgoacese* but Zeiller thinks 

 that it might be better to place it in the Conifer -«,t a position which has been given it 

 by Renault.^ Until one has more detailed knowledge of the structure of the fructifica- 

 tion, it seems impossible to refer the genus with any degree of satisfaction or certainty 

 to either of these groups. 



It is to be remembered that, in dealing with these Palaeozoic Gymnosperms, we may 

 be dealing with synthetic types which possessed characters that have now split up and 

 passed on to different though perhaps allied genera. § 



An excellent synopsis of the literature and species of Dicranophyllum has been 

 given by Reniek,|| some of which are, however, only known from very imperfect 

 material. 



Dicranophyllum anglicum Kidston, n. sp. 

 PL XIV. figs. 3 and 3a. 



Description. — Leaves close, about 3 "50 cm. long, spirally arranged on stem, and 

 dichotomising three or four times into slightly spreading narrow, linear, rigid, sharp- 

 pointed segments, from 1*25 mm. to 0*50 mm. wide according to position on leaf. 

 Undivided basal portion of leaf about 7 mm. long. 



Nervation at base of leaf not clearly shown, but one vein seems to enter it, which 

 dichotomises immediately, the two arms taking a submarginal position, one of which 

 passes into each of the two arms of the next bifurcation ; these again bifurcate almost 

 immediately on entering the segments, assume a marginal position, and pass into the 

 next dichotomy. The terminal segments have only a single central vein ; all the others 

 show two marginal veins, the result of a basal dichotomy of the single vein which 

 enters them. 



Remarks. — The only specimen of Dicranophyllum which I have met with in 

 Britain is that shown natural size on PI. XIV. fig. 3, which is contained in an ironstone 

 nodule. The stem is badly preserved and does not show the leaf attachments, except 

 of those which spring from the sides, whose relative position, however, clearly indicates 

 a spiral arrangement on the stem. The specimen is that of a comparatively young 

 branch, and the stem at its widest part is only 0*5 cm. broad. 



The leaves are about 3 "50 cm. long and 1*30 cm. wide, and a line drawn round the 

 apices of the segments would give a rhomboidal figure. The segments have been rigid, 

 and the arms of the dichotomies form an acute angle with a sharp-pointed sinus 

 between them. 



At the base of the leaves the nervation is not well seen, but as far as I can make 

 out, only one vein appears to enter the leaf, which immediately on entering bifurcates. 



* Potoni6, Lehrbuch, p. 289. t Elements, p. 255. 



I Flore f oss. terr. houil. de Commentry, part ii. p. 626, 1890. 

 § See also Seward and Gowan, Ann. of Bot., vol. xiv. p. 137, 1900. 

 || Ann. Sue. gSl. de Belgi<iue, vol. xxxiv., Memoires p. M., 193, 1907. 



