20 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 
J 
describes.” Mr. Strickland then points out the difference in the characters of the 
Coal-measure shells from those of Cardinia, and contends for a fresh-water habitat 
for the former. 
1844. In the same year Dr. Garner gave some drawings in the ‘ Natural 
History of the County of Stafford,’ pl. EK, of Coal-measure shells from the North 
Staffordshire coal-field ; but he neither named nor described them. Figs. 21, 22, 
appear to be Naiadites modiolaris ; fig. 19, Naiadites carinata ; figs. 20 and 23, 
three forms of Carbonicola. 
1845. In 1845 Murchison, von Keyserling, and de Verneuil (‘ Russia and the 
Ural Mountains,’ pl. xxi, fig. 9), and de Verneuil (‘ Paléontologie de la Russie,’ 
pl. xix, fig. 10), described and figured Unio Hichwaldianus as a Coal-measure form, 
closely allied to Unio subconstrictus, Sow., and Unio uniformis, Goldfuss, shells 
which probably belong to two different genera. 
In 1846 von Keyserling, in ‘ Petschoraland,’ &c., described Cardinia sub- 
porallela from Coal-measures. 
1850. In a memoir with the title of ‘Mélanges paléontologiques,’ part 1, 
published in 1850, P. de Ryckholt described and figured— 
Cardinia atrata, Goldfuss (not figured), Cardinia Scherpenzeeliana, Ryckh., 
3 Hullosiana, Ryckh., 5 salebrosa, Ryckh., 
3 colliculus, Rhyck., s macillenta, Ryckh., 
ms nucularis, Mytilus prepes, 
<3 Toillieziana, Ryckh., eo Wesemxlianus, 
>»  *ltans, »  Loillieziana, 
3 uncinata 3 Fontenoyanus, 
*Omaliusianus, | pe ligonula, 
*ampetilicola, »  fabalis, 
»  *cordolianus, » Geinitzianus, 
angulata, » divisus, 

mostly from the neighbourhood of Mons, Liége, and Tournay ; but those marked 
thus * were from Visé. Most of the forms described as Mytilus are young examples 
of Naiadites, but I think it possible that Posidonomya Gibsoni is imeluded 
amongst them. 
I have been to the Museums of Brussels and Liége, but have not been able 
to find the original specimens, although Professor Dewalque showed me many in 
his own collection named after Ryckholt; and at the former place there are 
also specimens with his name attached. It is highly probable that many of the 
forms named above are synonymous, and denote different stages of growth of 
the same shell. The name Mytilus prepes is given to Anthracomya Williamson 
(Bronn) at Brussels. With regard to those shells described as Cardinia, all 
the forms figured belong to <Anthracomya except C. Hulloziana, which is a 
Carbonicola. These Anthracomye are much embellished in the drawings, and 
