Carboniferous Fossils from Siam

F. R. Cowper Reed
1920 Geological Magazine  
Athyris subtilita (Hall). (PI. II, Fig. 10 .) /^VXE internal cast of the pedicle-valve of a species of Athyriŝ seems indistinguishable from A. subtilita Hall' which occurs in the Carboniferous of Belgium, 2 and has recently been recorded from Eastern Yunnan. 3 The general shape and narrow median sulcus, the concentric sublamellose growth-ridges, and small, parallel dental plates, are well seen in our specimen. Spirifer (Reticularia) cf. lineatus Martin. The peculiar and characteristic
more » ... cteristic ornamentation of Sp. lineatus is found on a fragment of a crushed valve in the collection. This well-known species occurs in the Culm of Hagen, according to Nebe/ as well as elsewhere. Camarophoria sp. (PL II, Figs. 11, 12.) There is the flattened impression and the cast of the left half of the valve of a small brachiopod, possessing characters which indicate its reference to the genus Camarophoria. The beak is not preserved, and it is doubtful if it is the brachial or pedicle valve with which we have to deal. The cardinal angles are rounded ; there are 4-6 faint, low, rounded ribs on each side of a median weak sinus, which also bears two or three ribs, but the lateral portions of the shell are devoid of ribs, and simply show a few strong concentric growthridges. These external characters seem to suggest a comparison with C. Dunkeri (Roemer) as interpreted by Holzapfel. 5 Another, but uncrushed specimen (PI. II, Fig. 12 ) consists of the internal cast of a pedicle-valve, 12'5 mm. long and 15 mm. wide, which shows the triangular spondylium. Productus concentricus Sarres-Kayser. (PI. II, Fig. 13 .) There is one brachial valve of a species of Productus which seems to correspond precisely with the form described and figured by Kayser 6 as Pr. concentricus Sarres, from the Rhenish Culm. Our specimen, which measures 9 mm. in width, shows the ornament and shape distinctly, and is fairly well preserved.
doi:10.1017/s0016756800101323 fatcat:bujipxzivfgcrni36qboxx2cmi