Carboniferous Fossils from Slain. 115 



recorded by Crick ' from the Coddon Hill Beds of Devonshire, which 

 are closely similar lithologically as well as faunistically with the 

 Siamese dejDosit, and the same species is a characteristic one of the 

 "Posidonienschiefer " of the Harz and of Geigen, near Hof . There 

 is apparently another species of Prolecanites or more probably 

 Nomismoceras represented in the collection, but it is too poorly 

 preserved for determination. 



Glyphioceras (?) sp. 



One slab of rock contains many much-crushed casts and 

 impressions of a subglobose cephalopod with a broad rounded back 

 and large convex outer whorl, slowly increasing in size, but almost 

 completely overlapping the inner whorls, which are exposed in 

 a small, deep, umbilicus with rectangular (?) edges. A few widely 

 distant concentric constrictions cross the outer whorl. This shell 

 may belong to the genus Glyphioceras (cf. Gl. mutabile Phill.),^ or to 

 Gastfioceras (cf. 6* (?) Kayseri Loczy,'' of the Carboniferous of 

 China), but there is not sufficient of it known to determine its 

 relations. Mansuy"* has doubtfully recorded the genus (rl^/^Aioceras 

 from the Carboniferous of Eastern Yunnan, but it is a well- 

 represented genus in the " Posidonienschiefer " of the Harz. 



Pleiirotomaria (Mourlonia) aff. conica Phillips. (PL II, Fig. 2.) 



There is one portion of a shell of a Pleiirotomaria half imbedded 

 in matrix and somewhat crushed, but it can be seen to have been 

 a low trochiform shell of 4-6 whorls, rapidly increasing in size 

 and with an aj)ical angle of 70-80 degrees. Each whorl is rather 

 sharply angulated at the band, which in the basal whorl is peripheral, 

 but on the upper whorls is situated a little distance above the 

 suture-line. The apical surface of the whorls is slightly excavated 

 just above the band, but becomes gently convex near the suture- 

 line. Below the band the umbilical surface of the basal whorl 

 seems to have been strongly convex, but it is rather crushed and 

 has a concentric fracture simulating a revolving ridge. The margins 

 of the band are sharp and jDrominent. The surface of the whorls 

 is crossed by strong, regular, transverse, curved striae, which are of 

 almost equal size and nearly equidistant, and they meet the band on 

 the apical surface at about 30 degrees or less, but apparently are 

 nearly at right angles to it below. Dimensions : height (estimated) 

 about 17 mm., basal diameter about 19 mm. With regard to its 



^ Crick, Quart. Journ. Geol. Soc, vol. Iv, 1895, p. 652. 



2 Phillips, Geol. Yorks, pt. ii, 1836, p. 236, pi. xx, fig. 26. Crick, Cat. Foss. 

 Ceph. Brit. Mas., pt. iii, 1897, p. 181 (and references). Holzapfel, Palceont. 

 Abhandl, vol. v, pt. i, 1889, p. 29, t. ii, figs. 2-6. 



^ Loczy, Wiss. Ergebn. Reise Szechenyi in Ostasien, Bd. iii, 1898, p. 44, t. i, 

 figs. 7,7a. Schellwien in Futterer's Durch Asien, Bd. iii, Lief, i, 1903, p. 139, 

 t. i, figs. 1, 2. 



* Mansuy, Mem. Surv. Geol. Indochine, vol. i, fasc. ii, 1912, p. 87, pi. xvi, 

 fig. 5. 



