32 Prof. T. R. Jones and Mr. J. W. Kirkby on 



K., of the marine beds of the Carboniferous Limestone series. 

 The latter is usually smaller than ordinary examples of Car- 

 bonia fabulina ; and its valves have not the same ventral 

 overlap. Otherwise it is not always an easy matter to distin- 

 guish them. 



Localities and Mode of Occurrence. — At Pittenweem, in 

 the Calciferous Sandstone series, about 800 feet below the 

 base of the Carboniferous Limestone, C. fabulina occurs 

 in blackband ironstone, associated with Carbonia Ranki- 

 niana, J. & K., Leperditia scotoburdigalensis (Hibbert) , 

 coprolites (possibly of Rhizodus), and the remains of Lepi- 

 dodendron. 



At Millburn, Campsie, in the Carboniferous Limestone 

 series, it is found in impure limestone, together with Spirorbis 

 carbonarius, Murch., and Stigmarian rootlets. 



In the same formation at Crossgatehall, near Edinburgh, it 

 is met with in ironstone, with C. Ranhiniana, C. pungens, 

 Spirorbis sp., and Lingula squamiformis, Phill. 



In the Coal-measures at Provanhall, Lanarkshire, it is 

 found in black carbonaceous shale, with fish-remains and 

 plants. 



Also in the same formation at Pirnie Colliery, Fifeshire, in 

 parrot-coal, with Carbonia Rankiniana, and associated with 

 the remains of the Amphibian Loxomma Allmani, Huxley, 

 and Fish, such as Strepsodus sauroides, Ag., Megalichthys 

 Ilibberti, Ag., Coslacanthus lepturus, Ag., Ctenodus sp., Pleura- 

 canthus gibbosus, Ag., and others; also Anthracomya pumilal ', 

 Salter, Spirorbis carbonarius, Murch. (attached in numbers to 

 drifted fragments of Sigillaria), and species of Antholites, 

 Lepidodendron, Calamites, and Stig?naria. 



At the same locality, on another horizon, the variety inflata 

 occurs in coarse ironstone, which is filled with fragments of 

 Calamites, the Entomostraca being found within the fllled-up 

 stems of the plants as well as in the matrix. A similar fact 

 was observed by Mr. John Young, who obtained a number of 

 examples of this species from the stem of a Lepidodendron, 

 at Possil, near Glasgow *. 



Near Hylton, west of Sunderland, it is met with high in 

 the Durham Coal-field, in a clayband ironstone, associated 

 with great numbers of an Estheria-like fossil, Ancghis? Vinfi, 

 Kirkby, Carbonia Ranlciniana, J. & K., Beyricltia arcuata 

 (Bean), a species of Antliracomya, Plant-remains, and the 

 wings of Orthopterous Insects. 



Other localities we give, with less detail, as follows : — 



* ' List of Carbon. Fossils of West of Scotlaud,' by John Young and 

 James Armstrong, p. 27. 



