PRODUCTUS. 163 



Productus proboscideus, Be VerneuU. PL XXXIII, figs. I — 4. 



Productus proboscideus, Be VerneuU. Bulletin de la Soc. Gcol. dc France, vol. xi, 



p. 259, pi. iii, fig. 3, 1840. 

 Clavagella prisca, Golcf/uss. Petref. Germ., vol. ii, p. 28"), pi. clx, fig. 17, 1841. 

 Productus proboscideus, V. Buck. Abhand. der. K. Akad. der Wisscns. zn Berlin, 



Erster Theil., p. 40, 1841. 

 — Be Koninck. Descript. des Animaux foss. du Terrain Carb. 



de Belgique, p. 11, fig. 4, 1843; and Mon. du genre 



Productus, pi. vi, fig. 4 «. »« c > * 1847. 



Spec. Char. Shell of moderate size, and very variable in shape, on account of the 

 singular prolongation of its ventral valve. Dorsal valve small, gently and regularly concave ; 

 slightly transverse or elongated, with a straight hinge-line always shorter than the greatest 

 width of the shell. Surface covered with fine, radiating, thread-like striae, intersected 

 by numerous concentric wrinkles. The ventral valve is composed of two well-marked 

 parts ; the first (which corresponds with almost the entire dorsal valve) is marginally 

 somewhat circular, moderately convex, and about as wide as long, the beak being very 

 small and but slightly incurved over the hinge-line of the opposite valve. Auriculate 

 expansions small. The second portion is composed of a general prolongation of the 

 margin of the same valve, which commences by the lateral portions extending on either 

 side, and, by gradually forcing open the smaller valve, unite round its margin, to be pro- 

 longed afterwards in the shape of a cylindrical tube of lesser or greater length. This 

 tube is concentrically wrinkled, and irregular in width and direction, while the surface of 

 the entire valve is minutely striated, and numerous long, slender spines rise and project 

 forwards from the lateral expansions of the ventral valve. Interior unknown. Pro- 

 portions very variable ; two British examples have measured 



Ventral valve, entire length, with tube, 13^, width 5, lines. 



Dorsal valve „ „ 4, „ 4|, „ 



Another example measured — 



Ventral valve, entire length, with tube, 11, width 4^, lines. 



Dorsal valve „ „ 3, „ 3^ „ 



Obs. This Productus is one of the most remarkable of the genus, and its discovery 



by Mr. Burrow in the Carboniferous limestone of Settle, in Yorkshire, was the more 



interesting from the fact that authentic examples of the species had not until then been 



found in any other locality than Vise, in Belgium. 1 The shell has been fully described and 



1 Another form, (?) nearly related by shape to that under description, has been described and figured by 

 Messrs. Norwood and Pratten from the Carboniferous rocks of Graysville, Illinois, America, under the 

 denomination of P. clavus, but which is stated by these palaeontologists to " differ from P. proboscideus, 

 with which alone it can be confounded, in the longitudinal ribs not extending over the visceral portion, 

 and in^the prolongation not showing the numerous and well-marked transverse folds of that species. The 



