CRITICAL BIBLIOGRAPHY. 13 
and I am the more inclined to this view from the examination of a specimen from 
that locality in the possession of Dr. John Young, Curator of the Hunterian 
Museum, Glasgow. About the figures, pl. xvi, figs. 5, 6, I must say I have great 
doubt as to the shells they are intended to represent. Ure says, “‘ Two species of 
mussel are found in Kilbride: those of the former are casts and rare; the latter 
are in ironstone and lie flat.” The former is possibly Naiadites, the latter 
Lingula. He figures on pl. xv, fig. 2, a shell which more closely resembles 
Anthracosia robusta than anything else I know, of which he says, “ The cockle 
is found very perfect in schists with Orthoceras, Encrinites, &c., at Black Craig 
and Thornley Bank.” I have, however, never known C. robusta to be associated 
with marine forms in Scotland, and Mr. James Nielson tells me that Carbonicola 
robusta never occurs in this locality. 
1809. The next to write on the subject appears to have been W. Martin, who 
brought out his ‘ Petrefacta Derbyensia’ in 1809 at Macclesfield ; and, although 
holding somewhat curious views of the true import of fossils, yet he was endowed 
with an acute observation. His figures and description are excellent; and his 
work is still a standard reference as containing the first descriptions and figures 
of many Carboniferous Limestone species. He seemed to consider that each 
fossil species was but the representation in stone of living forms, as is shown in 
his description, where he states, ‘‘ The hinge (visible only in recent species), &c.”’ 
He figures three specimens from ironstone, and I feel no doubt as to the form 
represented. The name ‘‘ Conchyliolithus (Mya ovalis)”’ is given to it. It is here 
to be noted that the Mya of Linneus equals Unio of Lamarck. 
1813. Sowerby, in 1813, published the vol. i of his ‘Mineral Conchology,’ 
containing a plate of Coal-measure shells, tab. xxxiii, figs. 1—3, 5—7, with short 
descriptions, pp. 83, 84, under the names Unio subconstrictus and U. acutus. The 
other figure on this plate (fig. 4) is said to have been obtained from marl at 
Felmersham, Bedfordshire, an Oolitic locality. I have examined the original 
Specimen in the Sowerby Collection in the British Museum (Natural History), 
South Kensington, and, from the matrix and characters, consider it to be a 
well-known Oolite shell; but, curiously enough, this Oolite shell, called Unio 
uniformis, was considered by Sowerby to be the same form as Martin’s Mya ovalis 
from the Coal-measures of Derbyshire, and the name was substituted because the 
former was in use for recent shells. 
1824. Defrance, in the ‘ Dictionnaire des Sciences naturelles,’ vol. xxxiii, 
p- 295, in 1824 followed Sowerby, but suggested that, as nothing of the interior 
was known, the genus was doubtful, and that the various forms described were 
simply variations. 
1828. Fleming, in his ‘ History of British Animals,’ 1828, quotes Unio acutus, 
Sow., giving, however, the locality as Middle Oolite, and Unio Urii, referring 
