26 Mr. R. Kidston on the 



Localities. — Monkton Collieiy, near Barnsley, and East 

 Gawber Colliery, Barnsley, Yorkshire. 



Horizon. — Middle Coal-measures; Shale over "Barnsley 

 Thick Coal." 



Cyclotheca, Kidston, n. g. 



Description. — Sporangia small, free, sessile^ circular, exan- 

 nulate, and arranged in two parallel rows. 



Remarhs. — In structure the individual sporangia approach 

 closely to those of MyriotJieca, Zeiller *, but in Myriotheca 

 the sporangia are oval and cover the whole of the lower sur- 

 face of the pinnules. 



In Renaultia, to which Cyclotheca has also some affinity in 

 the structure of the sporangia, the sporangia are situated at the 

 extremities of the veins either singly or in groups of from two 

 to five. Cyclotheca differs from both these genera in the 

 sporangia being circular and arranged in two parallel rows — 

 probably one row was situated on each side of the midrib of 

 the fruiting pinnule. 



Cyclotheca belongs to the Marattiacese, and is more closely 

 related by the structure of its sporangia to Angiojjteris than 

 to any other recent genus. 



Cyclotheca hiseriata^ Kidston, n. s. 

 (PI. I. figs. 10-12.) 



Description, — Characters of genus. The sporangia measure 

 ■50 millim. in diameter, and their walls are composed of small 

 cells not elongated more in one direction than the other. 



Remarks. — This species is founded on a single specimen 

 which was collected by Mr. P. Jack near Baillieston. Fig. 10 

 shows the fossil, natural size. It consists of several pinnee 

 lying on each side of the rachis, of which a small fragment 

 is shown towards the centre of the figure. With the excep- 

 tion of this fragment of rachis there is nothing preserved in 

 the fossil but the parallel rows of sporangia. These are well 

 preserved and shown at fig. 11, magnified six and a half 

 times. At fig. 12 are given four sporangia, magnified 

 twenty times. Although no trace of a midrib is shown, one 

 probably lay between the parallel rows of sporangia. 



The small specimens originally figured by Lesquereux as 

 titaphylopteris aster oides'\ probably belong to the genus 

 Cyclotheca. 



> * Ann. d. Sc. Nat. C^ ser. vol. xvi. Bot. p. 186, pi. ix. figs. 18-20 ; also 

 Flore fot^s. dn bassiu Iiouil. d. Valenciennes, p. 32, tig. 19. 

 t liep. Geol. Survey of lllin. vol. iv. pi. xi\'. figs. 8-10. 



