62 Proceedings of the Boyal Physical Society. 



sents the base and whicli the apex of the fossil, but probably 

 that marked a represents the basal extremity. 



Fig. 3 shows a small portion of an uncompressed example. 

 The segments are concave externally, and the sutures slightly 

 winged. At the part marked a (Fig. 3) the impression of the 

 segments of the opposite side is seen. This example shows 

 clearly that when such fossils become compressed the spiral 

 segments of one side crossing obliquely those of the other 

 side must, when flattened, produce on the surface of the fossil 

 a series of rhomboidal markings. 



Palceoxyris appendiculata (Lesquereux) appears to be only 

 a somewhat distorted example of Fcdceoxyris carhonaria. 



Horizon. — Coal measures. 



Localities. — Clays Croft Openwork, Coseley, near Dudley, 

 Staffordshire ; Woodhill Quarry, Kilmaurs, Ayrshire. 



Pal^oxyeis Prendelii, Lesquereux. 

 (PL I, Figs. 4, 5.) 



Palceoxyris Prendelii. 



Lesquereux {in part), Eeport, Geol. Survey of Illinois, vol. iv., p. 464, 

 pi. xxvii., fig. 12. 1870. (Excl. fig. 10.) 

 S2} irangium Prende Hi. 



Lesquereux [in part), Coal Flora of Pennsyl., vol. ii., p. 519, pi. Ixxv., 



fig. 13. 1880. (Excl. figs. 14 and 15.) 

 Sclumper {in part), Traite d. paleont. veget., vol. iii., p. 585. 1874. 



Descri^ption. — Body fusiform ; segments 6 (or 8) equally 

 broad, from 2*5 mm. to 3 mm. wide. 



Remarks. — This species is distinguished from Palceoxyris 

 carhonaria by its broader segments and steeper spirals, and 

 from Palceoxyris helicteroides by its segments being equal 

 in width. From the two following species it is easily 

 separated by the width and number of their segments. 

 Fig. 4 shows a large specimen. At the part marked 

 a the segments form an almost straight beak-like point; 

 at the other extremity they are more twisted. These 

 differences correspond to those already mentioned in the 

 description of Pcdceoxyris carhonaria. At Fig. 5 is drawn 

 a small uncompressed example. The sutures are elevated, 

 and form a distinct " collerette." The surface of the 



