PRODUCTUS. 171 



Productus fimbriatus, J. de C. Sowerby. PI. XXXIII, figs. 12— 1 5, and PI. XLIV, fig.15. 



Anomites punctatus, Martin. Pctrif. Derb., pi. xxxvii, figs. 7, 8 (fig. 6 exclusa), 1809. 

 Productus fimbriatus, J. de C. Sow. Min. Conch., pi. 459, fig. 1, July, 1823. 

 Strophomena marsupit, Davreux. Const. Geogn. de la proviuce de Liege, pi. iv, fig. 2 a, b, 



1833. 

 Producta fimbriata, Phillips. Geol. of York., vol. ii, pi. viii, figs. 11, 12, 1836. 



— — V. Buck. Abhandl. der K. Akad. der Wissens. zu Berlin, Theil i, 



p. 27, pi. ii, figs. 21—23, 1841. 



— — De Koninclc. Desc. des Animaux foss. du Terr. Carb. de Belgique, 



pi. x, fig. 3 a > *» <*><*> 1843 ; and Mon. du genre Productus, pi. xii, 

 fig. 3 «■*.'. 1847. 

 1 Producta laciniata, M 'Coy. Synopsis of the Carboniferous Fossils of Ireland, pi. xx, 



fig. 12, 1844. 

 Producta fimbriata, M'Coy. British Palaeozoic Fossils, p. 461, 1855. 



— — Dav. Mon. of Scottish Carb. Brach., pi. ii, fig. 27, I860. 



Spec. Char. Longitudinally oval or ovate ; hinge-line a little shorter than the width of 

 the shell. Ventral valve uniformly convex, gibbous, and greatly arched in profile ; beak 

 much incurved, overlying the hinge-line at its attenuated extremity ; ears small and but 

 slightly marked. Surface regularly traversed by numerous sub-regular, concentric, promi- 

 nent bands or ridges, with flattened, intervening spaces ; a row of elongated tubercules cover- 

 ing each ridge, and from which project long, tubular, cylindrical spines. Dorsal valve 

 nearly flat or moderately concave, traversed by numerous concentric ridges, with concave 

 interspaces ; a row of short, adpressed spines projecting from every ridge. Dimensions 

 variable ; two specimens have measured — 



Length 18, width 17, greatest depth between valves 9 lines. 



"I K 1 o 7 



Obs. This species does not attain the proportions of P. punctatus, is less variable 

 in its shapes, possesses no sinus, and is especially distinguished by the single row of 

 cylindrical spines which rise from each row of elongated tubercules, as above de- 

 scribed. With P. laciniata, M'Coy (PL XLIV, fig. 15), I am not sufficiently 

 acquainted. It has been supposed by some a synonym of P. punctatus, but the study 

 of two Irish examples leads me almost to agree with M'Coy while stating that it bears 

 more resemblance to P. fimbriatus, of which it is possibly only a variety or variation 

 in shape, more transverse, with a greater number of concentric ridges, smaller and more 

 numerous elongated tubercules or cylindrical spines. 1 This I must, however, leave as an open 

 question for the present. The interior of the dorsal valve of P. fimbriatus alone is at present 



1 At p. 110 of the 'Synopsis,' M'Coy describes his P. laciniata as "nearly semicircular, length one 

 sixth less than the width; hinge-line rather less than the width of the shell; moderately convex; beak 

 small, prominent ; ten or twelve rounded, concentric wrinkles, fringed on their marginal declivity with 

 close, regular, lengthened spine-bases. Length eleven lines; width one inch one line." Fig. 15 of our 

 44th plate is taken from the original specimen. 



