PRODUCTUS. 175 



very slightly concave, traversed by small wrinkles and minute concentric lines of growth, 

 a few elongated tubercule-pits being also irregularly scattered over the visceral portion of 

 the valve. Length 5, breadth 0, greatest depth between the valves 2 lines. 



Obs. As observed by Prof, de Koninck, this species is distinguished from P. aculeatm 

 by its smaller dimensions, more transverse shape, slight median depression, and lesser 

 concavity of its smaller valve. The spiny tubercules are not scattered over the entire surface 

 of the ventral valve, as in Martin's species, but are restricted to the visceral portion of the 

 valve. The interior is very similar to that of other Prodttcta. P. Kcyxcrlingianus is not a 

 rare fossil in the Carboniferous limestone of Settle, in Yorkshire, but much less so in that 

 of Derbyshire. I am not acquainted with any specimens from either Scotland or Ireland. 



On the Continent it occurs at Vise, in Belgium, as well as at Likwin, Government of 

 Kalouga, and of Cosatchi-Datchi, Ural. 



Productus spinulosus, /. iSoiverby. PI. XXXIV, figs. IS — 21. 



Produotus spinulosus, J. Sow. Min. Conch., pi. Ixviii, fig. 3, Oct., 1814. 

 Producta granulosa, Phillips. Geol. of Yorks., pi. vii, fig. 15, 1836. 



— cancrini, De Kon. Desc. des Anim. foss. du Terrain Carb. de Belgique, pi. ix, 



fig. 3 (not of De Verneuil), 1843. 



— papillatus, De Kon. lb., pi. x, fig. 6. 



— granulosus, De Kon. Mon. du genre Productus, pi. xvi, fig. 7, 1847. 



— — M'Coy. British Palaeozoic Fossils, p. 472, 1855. 



Dav. Scottish Carb. Brach., pi. iv, figs. 22—24, 1861. 



Spec. Char. Shell transversely semicular ; hinge-line a little shorter than the greatest 

 width of the shell. Ventral valve regularly convex and evenly arched, without sinus; 

 beak incurved, but not overlying the hinge-line, except at its attenuated extremity ; ears 

 flattened, with a few concentric wrinkles ; surface covered with sub-regular, small, slightly 

 elongated tubercules, irregularly or quincuncially arranged, each tubercule producing a 

 slender spine. The tubercules are more often about half a line or so apart near the middle 

 of the shell, but closer as they approach the beak. Dorsal valve deeply and evenly concave, 

 and covered with small tubercule-pits, arranged somewhat in quincunx. Interior 

 unknown. Length 7, width 9 lines. 



Obs. This species does not appear to have attained proportions very much larger 

 than those above recorded, and is easily distinguished from all other British Producta by 

 shape and sculpture. To those examples in which the tubercules or spines were regularly 

 arranged in quincunx the term spinulosus has been applied, while to those in which the spines 

 or tubercules were less regularly disposed the term granulosus was given. I quite coincide, 

 however, in the opinion expressed by Prof. M'Coy, that the two are simply different 

 conditions of the same species, and should be therefore united. Prof. M'Coy is also of 

 opinion that P. KonincManus, De Verneuil, is distinct, and it is probable that P. spinu- 



