S9'2  ME. F. BOLTON, F.K.8.E., OX [Feb., 1904. 



extreme rarity of specimens, and the difficulty of sufficiently 

 clearing tliem from the matrix to determine their species, 

 have acted as deterrents to investigators. 



The few which do occur can be divided into three groups, 

 'according to their form. Those of least rarity are usually 

 found flattened in the shales, and are turreted shells of from 

 five to eight whorls, either with smooth surfaces or marked 

 by transverse ridges. They have been classed with 

 Buccinum, Turritella, Loxonema, Macrocheilus, Melania 

 and Eissoa. 



It is very probable that most of them will be found 

 to fall ultimately into the families Melaniidae and 

 Rissoidae. 



The second group includes two or three forms in which 

 the last or body chamber is much swollen, and the spire 

 relatively inconspicuous. It includes forms apparently 

 belonging to the genera Natica and Naticopsis. To the 

 third group belong shells of a Bellerophon type. Seven 

 species of the latter genus are recorded from the English 

 Lower Coal Measures, and one (B. Urii) from the Middle 

 .series. 



I have found gasteropod shells of a Melania type on two 

 or three occasions in the shales lying between the Bullion 

 or Upper Foot Seam, and the Upper Mountain Mine in the 

 'Rossendale district. 



From " Bawm-pots '' taken from the roof of the Bullion 

 or Upper Foot seam in the Bacup district, I have obtained 

 'several specimens of a small shell — Baphistoma (?) ornata — 

 and in several collections of fossils from the same horizon, 

 but where the Bullion seam is joined to the Gannister to 

 ■form the Mountain Four Feet, as at Carre Heys, Colne, is 

 to be found a small but very perfect shell — Naticopsis 

 globularis. 



