56 SUPPLEMENT TO THE 



Brachiopoda. At p. 380 he adds a " Note on the Species of Lingula from Sloly Quarry," 

 and says, " The small Lingula which is found in such abundance at Sloly Quarry was 

 named by Mr. Salter L. mota (' Quart. Journ. Geol. Soc./ vol. xix, p. 4S0), and in the 

 ' Catalogue of Eossils in the Museum of Practical Geology ' it is called L. hyhrida. Mr. 

 Davidson, in his ' Monograph of the Devonian Brachiopoda,' refers it to the Carboniferous 

 species L. squa7niformis, and remarks that ' it is difficult to obtain specimens preserving 

 their natural shape, almost every example being deformed or put out of shape from the 

 effects of pressure or cleavage.' L. squamiformis is described as 'longitudinally 

 oblong, one third or less longer than wide ; valves slightly convex, with their external 

 surface covered with numerous fine concentric striae or lines of growth. Usual dimen- 

 sions 9 lines in length by 5 in width.' Taking this as the specific character of the 

 shell, we find at Sloly that, besides L. squamiformis there is also another Lingula^ which 

 must be either a new species or, at least, a well-defined variety. A comparison of a 

 great number of specimens shows that the breadth of this shell is equal to its length, or 

 nearly so. Dimensions 5 lines in length by 5 in width. Valves convex, and generally 

 marked with two lines of growth. Numerous fine intermediate stria3 cover the surface of 

 the valves, and give them a peculiar laminated appearance. Should this Lingula prove to 

 be a new species, the name L. circularis might be appropriate, since it differs so materially 

 from the other Lingula in having a form which is nearly orbicular. I should, perhaps, 

 add that the difference in shape from Ling, squamiformis could scarcely be due to distor- 

 tion, effected by either cleavage or pressure ; and I have observed, that when several 

 individuals of the two species occur on the same slab of slate they in every case have 

 retained their independent and characteristic form." 



Lingulce appear to be rare in the Devonian rocks of Great Britain. Schnur, in his 

 * Beschreibung Eifel. Brachiopoden,' p. 229, pi. xliii, fig. 6, describes and figures 

 a Lingula by the name of Lingula Konincki which bears some resemblance to some of 

 the Sloly specimens. Dr. Kayser also, in p. 642 of his ' Brach. des Eifel,' alludes to the 

 subject. Lingulce, where the genus occurs, should be abundant ; but it is not always so ; 

 for, although many thousands of specimens of Brachiopoda have been collected in the 

 Devonian rocks at Ferques, near Boulogne, only one or two examples of a Lingula were 

 procured by Mr. Bouchard ; and, although I spent many months in searching those 

 quarries, and their debris, I never saw a trace of the species. Discina was equally rare, 

 but Crania was not so scarce, although found only in one or two places. 



