312 MR ROBERT KIDSTON ON THE FOSSIL PLANTS OF THE 



Description. — Internodes vefy short, arched ; large scars periodic, distant ; ribs 

 prominent, with deep dividing furrows, generally continuous, much more rarely alter- 

 nating at the nodes, and running together at the branch-scars. Envelope surrounding 

 pit cavity of considerable thickness. 



Remarks. — Under this name have frequently been figured plants belonging to more 

 than one species. Brongniart himself seems to have included two species under it. 

 His figures 7, 8, pi. xv., and fig. 1, pi. xxiv., appear to be specifically distinct from the 

 plants figured on pi. xxiv. figs. 2, 3. These latter I regard as the true Catamites 

 approximata, and the former are probably to be referred to the Catamites Schiitzei, 

 Stur.* The Catamites approximatus, L. and H.,t is to be referred to Catamites 

 cruciatus, var. senarius, Weiss, \ and their Catamites approximatus, vol. i. pi. lxxvii., 

 probably to C. Schiitzei, Stur. To this last species should, perhaps, also be referred the 

 Catamites approximatus, Artis.§ 



Very little is known about the true characters of this species, the only specimens yet 

 discovered being merely casts of the pith cavity, from which the above imperfect descrip- 

 tion is drawn up. Of the two specimens figured, that on Plate II. fig. 5, at the point 

 marked with the a, indicates the position of one of the verticils of branch-scars ; below 

 it are fifteen internodes without any trace of another verticil of branch-scars. In the 

 fine specimen figured by Weiss (toe. cit.) the internodes between the verticils of large scars 

 are seven to eight. On the other specimen, figured on Plate II. fig. 6, there are nineteen 

 very short internodes, on none of which are any traces of branch-scars. On fig. 5, 

 between the line indicated at b, is a carbonaceous staining on the stone, which indicates 

 the thickness of the vascular elements, or of both vascular tissues and bark, the 

 distinction of the parts not being possible in the present condition of the fossil. The 

 fossil shows, however, that the pith cavity, represented by its cast (which has often 

 erroneously been supposed to represent the complete stem), was surrounded by a thick 

 envelope. The two specimens of Caiamitina approximata which I figure, and which 

 are two of only a small number of specimens seen from Ayrshire, show, as has 

 already been observed in the case of Catamitina verticiltata, that, as a rule, the ribs 

 do not alternate at the nodes. This is also seen on the figure given by Weiss, to 

 which I have already referred. In this character they show some approach to the 

 genus Asterocatamites. I do not give any measurements in the descriptions, as 

 the specimens are photographed natural size, and in minor details measurements 

 vary on different specimens, though the characters given in the description seem to 

 be constant. 



The two specimens figured have been communicated to me by the Rev. D. 

 Landsborough. 



* Sitzungsb. der k. Alcad. der Wiss., 1 Abth. vol. lxxxiii., 1881, p. 416, pi. i. fig. 1. 



t Fossil Flora, vol. ii. pi. ccxvi. 



} See Trans. Roy. Soc. Edin., vol. xxxiii. p. 340, fig. 1. 



§ Antediluvian Phytology, pi. iv: 



