376 MR ROBERT KIDSTON ON THE FOSSIL FLORA OF THE 



Referring to the specific value of Pec. Miltoni, Artis, sp., and Pec. abbreviata, 

 Brongt., Zeiller says : — " In regard to the question whether Pec. Miltoni and 

 Pec. abbreviata are not identical, and of which Pec. Miltoni is the older name, 

 having been founded in 1825, though not arriving at a wholly sure conclusion, 

 I incline meanwhile towards the negative. 



" The general form of the pinnules indicated by Artis appears very analogous 

 to those of Pec. abbreviata, but the nervation is not figured, which renders a 

 comparison almost impossible, this character being almost the only one by 

 which one is able satisfactorily to support it ; further, the figure and diagnoses 

 given by the author indicate the sori to be marginal, or almost marginal, while 

 I have already mentioned that the groups of capsules of Pec. abbreviata cover 

 all the inferior surface of the pinnule, and are by no means marginal. The 

 figures given by Geinitz, under the name of Cyatheites Miltoni,* show likewise 

 the fructification almost marginal (pi. xxx. figs. 6, 6a, and also Cyatheites Miltoni 

 var. abbreviates, figs. 8, 8a, and 8b). This character of the disposition of the 

 sori appears to me sufficiently important to compel one to regard Pec. abbreviata 

 as decidedly distinct from Pec. Miltoni. When, as to its union with Pec. poly- 

 morpha, proposed by various authors, it is hardly necessary to mention that the 

 characters of the fructification separate absolutely these two species, Pec. 

 abbreviata having the short capsules of Asterotheca, and Pec. polymorpha the 

 long sharp capsules of Scolecopteris. They belong further to different horizons" 

 (" niveaux differents ").t 



I must first refer to Pec. Miltoni as being of older date than Pec. abbreviata. 

 As is frequently the case with Pec. abbreviata, in Pec. Miltoni the nerva- 

 tion is seldom shown on account of the dense villosity with which the upper 



surface of the pinnules is covered. This 



villosity is in all respects identical to that 



occurring on the pinnules of specimens which 



have been distinguished as Pec. abbreviata, 



'•$£: & Brongt., from the Radstock Series. At text 



''Mm^m (^Pvrw ^& - ^ * s S* ven an enlarged drawing of three 



^B«fi. v -^J-d pTN - . pinnules of Pec. Miltoni, Artis, sp., from 



Pecopteris Mnioni, Artis, s P . Claycross, to show the nervation. This is 



Fi' 2. From Bardsley Colliery, Ashton-under- , . , . , ... „ . ./, ., 



Lyne, Lancashire. absolutely identical in all respects with the 



Figs. 3, 4. From Claycross, Derbyshire (Middle en l ar cr emen t f PeC. abbretiata, given by 



Coal Measures). & ' ° J 



Figures enlarged two diameters. BltONGNIART On llis pi. CXV. fig. 3«. There 



can be no doubt that the plant occurring at Claycross, Derbyshire (Middle 

 Coal Measures), is the true Pec. Miltoni, as its growth, segmentation, and the 



* Vers. d. Steinkf. in Sachsen, p. 27, pi. xxx. figs. 5-8; pi. xxxi. figs. 1-4. 



t Zeiller, Notes sur la florc howllere ties Asturies, p. 13. I may remark in passing, that in 

 England Pec. polymorpha and Pec. Miltoni (including Pec. abbreviata) occur on tho same horizon. 



