Vol. XXviii.] PAL^ONTOLOGr OF LANCASHIRE COAL MEASURES. 593 



I am strongly inclined to think that the specimens recorded 

 as C. rugosa and which are all more or less eroded, will yet 

 prove to be examples of C. robusta.* 



The specimen from Cant Clough, figured by Dr. Hind in 

 his monograph on Carbonicola, pi. II. fig. 7, is much more 

 likely to be from the Middle or Lower Coal Measures than 

 from the Yoredales. 



Carbonicola nvcularis (?) (Hind). 



From the Stubbs Mine at Bardsley. (W. 542, e. coll. 

 Wild, M.M.) 



From ''Mountain Mine" of Wigan. (Dr. Hind, Pal. 

 Soc, Mong. on Carbonicola, &c„ p. 63.) 



Carbonicola aquilina (Sow). 



From over the Stubbs Mine at Bardsley Colliery. (W. 

 545-550 e. coll. Wild, M.M.) 



From 12 inches above the Stubbs Mine at Banksfield 

 Tunnel, Bardsley. (W. 555., e. coll. Wild, M.M.f) 



From the Yard Coal at Old Hall, three-quarters of a mile 

 S.W. of Little Lever. (Salter, Geol. Surv. Mem., Geology 

 of Country around Bolton-le-Moors, p. 41.) 



From the Cannel Mine at Moss House, 3^. miles S.W. of 

 Bolton. (Salter, op. cit., p. 41.) 



From the Ashclough or Bin Coal at Shoretop, one mile 

 S.E. of Little Lever. (Salter, op. cit., p. 41.) 



♦Since writing the above I have found the following note: '• It appears 

 to me, judging from all the specimens I saw at Manchester, certain that 

 A. rugosa of Brown is the same species," i.e., A. robusta. (Salter, Geol. 

 Surv., Mem., Geology of Country around Wigan, p. 36.) 



t These seven specimens are of special interest as they were found in 

 association with 13 specimens of C. turgida, in nine square inches of space. 

 The growth of various species of Carbonicola in close association will 

 probably be found to have an important bearing upon the validity of 

 several forms now regarded as distinct species, the more so because in any 

 large collection of Carbonicola, it is easily possible to arrange gradational 

 series between two and even more species. This is especially true of the 

 species, C. acuta, C. aquilina, and C. turgida, and the sub-species of C. 

 acuta, all of which are linked up by intermediate varietal forms. 



