180 



they belong to the genus Myoconcha] on the other hand 

 the specimens cannot be identified with any species hitherto 

 described. The species Myoconcha elongata, Morris and Lycett^) 

 approaches them most nearly ; they are, however, considerably 

 larger and narrower in proportion. 



In the collection of Cape Stewart fossils examined by 

 Ltjndgren, there is a badly preserved impression in coarse brown 

 sandstone of the inner side of a Lamellibranch shell, which 

 Lundgren was unable to determine with certainty. This im- 

 pression is about 95""" long and 26°"° wide. It resembles the 

 casts of Myoconcha grönlandica and is probably to be identified 

 with this species. 



Trigonia. Brüguiere. 

 Trigonia undulata. Fromherz. 



PI. VI, fig. 11. 



1872 — 79. Ltcett, J. A monograph of the British fossil Trigoniœ. Printed 

 for the Palæontographical Society. London, p. 77, tab. XVI, fig. 9, 

 10, 11; tab. XVII. fig. .5, 6. 



Six specimens of a species of Trigonia occur in a fine or 

 fairly coarse-grained sandstone from Mount Nathorst. These 

 agree exactly with Lycett's description of Trigonia undulata 

 and with figure 5 on pi. 17 of his work, except that they are 

 slightly more convex and consequently the border between the 

 surface of the shell and the area is bent more in an S-figure. 

 The Greenland specimens are also more convex than a specimen 

 of the same shell from the Bathonian of Boulogne-sur-mer 

 in the Munich Collection, although in other respects they 

 resemble it exactly. 



Trigonia undulata is quoted from the Great Oolite and 

 Stonesfield slate, from the Forest Marble and Bradford Clay 



*) Morris, J., and Ltcett, J. 1853. A monograph of the moUusea from 

 the Great Oolite. Partit. Bivalves. London, p. 77, pi. Ill, fig. 18. 



