326 CARBONIFEROUS LAMELLIBRANCHIATA. 



the description of Cardiomorpha glebosa,de Ryckholt, I see no reason to think the 

 shells distinct, and am of opinion that it is highly probable that the two species 

 are the same. Unfortunately, de Ryckholt's specimens cannot be examined, and 

 therefore some slight degree of uncertainty must remain. De Koninck's type 

 came from Vise, de Ryckholt's from Tournai. The latter shell measured 37 mm. 

 antero-posteriorly, 27 mm. from above downwards. I think that the Pholadomya 

 Tornacensls, de Koninck, should also be placed under this species. 



British specimens of E. lamlnata have, curiously enough, generally been 

 referred to Pullastra crassistria, M'Coy, and not to Astarte quadrata, M'Coy, 

 which has been shown to be identical with Phillips's species. The type of the 

 former species is so very imperfect as to be quite unrecognisable, but enough of 

 the external surface remains to render it certain that the E. lamlnata, Phillips, 

 sp., and Pullastra crassistria, M'Coy, are quite distinct. 



Fig. 31, PI. XXXVI, a specimen from Park Hill in the Collection of the 

 Geological Survey, Jermyn Street, is the largest example I have seen, being 

 larger than Phillips's type, PI. XXXVI, fig. 11. Specimens in the younger stages 

 of growth are relatively more transverse than adults, and there seems to be a 

 large amount of variation in the size and number of the concentric ridges. It 

 seems to me to be probable that the Solenopsis parallela, de Ryckholt, may be a 

 very large example of this genus. 



I have procured a fair number of specimens from Thorpe Cloud, in all stages 

 of growth, which demonstrate the gradual changes of contour with increasing 

 age. Unfortunately, so far, I have not been able to collect examples exhibiting 

 any details of the interior, nor to assure myself that the shell possesses the 

 characteristic ossicle of the genus. There appears to have been some considerable 

 amount of variation in the number and size of the concentric ridges and grooves, 

 some half-grown examples showing much larger and more widely separated ridges 

 than many of the more fully-grown examples. 



De Koninck, in 1842 (op. supra c'tt.), figured a specimen from Tournai which he 

 referred to the genus Cardinia ? and which he thought to be identical with Phillips's 

 shell, but he does not appear to have retained the species in his second work. I 

 think that Cardiomorpha sulcata, 1842, of this author is also a synonym of the 

 species under description. This species is also not mentioned in de Koninck's 

 later work. A well-marked variety of E. lamlnata occurs in the same beds at 

 Thorpe Cloud (see p. 327). 



