60 Proceedings of the Royal Physical Society. 



centre, but whether this common centre is the node of a 

 stem or the termination of a branch, cannot be satisfactorily 

 determined. 



In the descriptions of the following species, I have used 

 the term " segment " to denote their component parts, as the 

 words "leaves" or "carpels" convey the notion that the 

 fossils are seed-vessels, an opinion not yet satisfactorily 

 established by proof. 



SYNOPSIS OF BEITISH SPECIES. 



Pal^oxyeis helicteroides, Morris sp. 

 (PL I, Fig. 1.) 



Carpolitlies helicteroides. 



Morris, Trans. Geol. Soc, London, 2d ser., vol. v. Explanation to figs. 



12 and 12«, pi. xxxviii. 1840. 

 Bronn, Index palajont, p. 239. 1848. 

 Goppert and Berger, De fruct. et semin., p, 16. 1848. 

 Spirangiuvi Preiulelii. 



Lesquereux (in jyart), Coal Flora of Peunsyl., vol. ii., p. 519, pi. Ixxv., 



fig. 15. 1880. 

 Schimper, Traite d. paleont. veget., vol. iii., p. 585. 

 Palccoxyris Prcnclelii. 



Lesquereux {in part), Report, Geol. Survey of Illinois, vol. iv., p. 466, 

 pi. xxvii., fig. 10. 1870. 



Description. — Body fusiform, 5 or 6 cm. long and 1 cm. or 

 more broad, composed of 6 or 7 alternate broader and 

 narrower segments ; the broader 4 to 5 mm. wide, the nar- 

 rower 1 to I'D mm. wide. 



Bemctrks. — This species is easily distinguished by the 

 segments being alternately wider and narrower. The seg- 

 ments are concave on their outer surface. 



Morris, in his description of this fossil, describes it as 

 " Carpella, 4 or 5 ; twisted spirally, but not close together." 

 He has evidently mistaken the narrow segments for intervals 

 between the broader segments. From the examination of 

 well preserved specimens, I have, however, no doubt that the 

 supposed intervals are only narrower segments. 



One of the specimens described by Lesquereux as Palce- 

 oxyris Prenclelii, appears to belong to this species, though 

 his figure is a little larger than the British examples. 



