DAVIDSON — SCOTTISH CARBONIFEROUS BRACHIOPODA. 



221 



Until within a twelvemonth since, or less, Scottish and other geologists had 

 been in the habit of distinguishing the Chonetes we are now describing by the 

 name Hardremis ; subsequently, from finding at p. 206 of the " Monographic 

 du Genre Chonetes" that Prof, de Koninck had referred the shell, pi. xvi., figs. 

 10-11 of Ure's " History of Rutherglen, etc.," to D'Orbigny's C. variolata, the 

 last-mentioned name was by many adopted for the species, and likewise so 

 labelled upon the tablets in the Museum of Practical Geology. With the desire 

 to arrive, if possible, at a correct identification, I forwarded several specimens 

 of the Scottish shell to Prof, de Koninck, in order to ascertain whether he was 

 satisfied that the shell in question really belonged to D'Orbigny's species, as 

 had been so stated to be in his " Monographic ;" and in answer 1 was informed 

 that he had subsequently determined that our shell could not be referred to 

 C. variolata, which last possessed finer and more numerous striae ; that the 

 Scottish shell occurred also at Yise, in Belgium ; and that he had intended to 

 describe it in the supplement to his " Monographic" by the name of C. alternata. 

 1 must also mention that having obtained from Sir Kichard Grifiith the loan of 

 Prof. M'Coy's various so-termed species of Chonetes, it did appear to me that 

 several among them, such as C. sulcata, C. volva, C. gibberula, and one or two 

 others should be united into a single species, and that they were likewise 

 specifically undistinguishable from our Scottish shell (?) ; but here again my 

 distinguished Belgian friend disagreed with me ; for although he was prepared 

 to admit that C. volva, C. sulcata, C. crassistria, and C. gibberula should be 

 united into a single species, he still considered his C. alternata — our Scottish 

 shell — as specifically distinct. 1 also received from Prof. Phillips the loan of 

 his four best and figured examples of C. Hardrensis ; and having compared 

 these with several of our Scottish specimens, the result was that I could per- 

 ceive no differences in the shape, areas, and striation, so that 1 deemed it pre- 

 ferable to allow our Scottish Cho7ietes to retain the name Hardrensis until the 

 subject might be further discussed. But I am, however, unable to perceive 

 what led Professor Phillips to suppose that his species was provided with 

 " large cordiform muscidar impressions ;" and in conclusion I must also observe 

 that although the ribs of C. variolata appear to be finer and more numerous than 

 is the case with the generality of specimens of C. Hardrensis, there does not 

 appear to exist much difference in the shape of the Scottish and American 

 species. 



C. Hardrensis is found at Gare, in Lanarkshire, at two hundred and thirty- 

 nine fathoms below " Ell coal ;" three hundred and forty-three at Raes Gill ; 

 three hundred and fifty -six at Hillhead. It occurs also at Capel Rig, East 

 Kilbride ; Auchentibber and Calderside, High Blantyre ; Brockley and Middle- 

 holm, near Lesmahago ; and Bobroyston, north of Glasgow. In Renfrew- 

 shire, at Arden- and Orchard-quarries, Thornliebank. In Stirlingshire, in 

 various stages, such as Craigenglen, Mill Burn, the Campsie main limestone, 

 Corrie Burn, etc. In Ayrshire, at West Broadstone, Beith ; Auchenskeigh, 

 Dairy ; Goldcraig, Kilwinning ; Hallerhirst, Stevenston, and Craigie, near Kil- 

 marnock. In Haddingtonshire, at East Barns, near Dunbar. It has also been 

 found in Eifeshire and in the island of Arran. 



XLIII. — Chonetes Buchiai^a. De Koninck. PI. ii., fig. 1. 



Chonetes BucJiiana. De Koninck's "Description des Animaux Eossiles du 

 Terrain Carbonifere de la Belgique," p. 208, pi. xiii., fig. 1, 1843 ; and 

 " Monographic du Genre Chonetes," p. 218, pi. xx,, fig. 17. 



The valves in this species are concavo-convex, and marginally semi-circular, 

 with a straight hinge-line as long as the greatest width of the shell. The 

 ventral valve is moderatelv convex, and somewhat flattened near the hinge-line, 



