36 



BRITISH PERMIAN BRACHIOPODA. 



Productus horridus abounds in the shell limestone of Humbleton and Tunstall hills ; 

 at the North Point, near Shields ; Westol, Hylton Castle, Dalton-le-Dale, Durham ; and 

 in the compact limestone of Midderidge, Garmundsway, as well as in the Breccia at 

 Tynemouth Cliff. It is also mentioned from Derbyshire. On the Continent it is found 

 in the lower Zechstein of Ropsen, near Gera; Ilmanau, Konitz, between Bucha and 

 Gosswitz, Glucksbrunn ; and on the meridial border of the Shuringer Wald, Possneck ; 

 Corbusen, near Ronnebourg ; in Silesia, at Lauban on the Gneis. It was also recognised 

 by M. De Koninck among the fossils brought back by M. E. Robert from Bell Sound, 

 at Spitzberg, &c. 



C. 



Productus latirostratus, Howse} Plate IV, figs. 1- — 12. 



Productus latirostratus, Howse. Catalogue of the Fossils of the Permian System 



of the Counties of Northumberland and Durham, in the 

 Transactions of the Tyneside Naturalists' Field Club, 

 vol. i, part hi, p. 256, 17th of August, 1848 ; and Ann. 

 and Mag. of Nat Hist., vol. xix, 2d series, p. 46, pi. iv, 

 figs. 1, 2, 1857. 



they may perhaps hereafter be found to have been connected with the vascular system. This idea is 



somewhat strengthened by the appearance 

 of similar lines on some casts of Spirifer, 

 which few persons would hesitate to pro- 

 nounce as vascular sinuses." (' Annals and 

 Mag. of Nat. Hist.' vol. xix, p. 46, 1837.) 

 This view of Mr. Howse's relating to 

 the interpretation of the reniform impres- 

 sions is new, and would require some fur- 

 ther investigation and confirmation before 

 final admission, as it does not entirely agree 

 with the notion entertained by Mr. Wood- 

 ward, myself, and others, as to the probable 

 form and position of the fleshy arms, 

 which appear to have produced peculiar 

 markings visible in the interior of both 

 valves of several species of Productus; 

 and in P. giganteus in particular, would 

 appear to have been small, and vertically 

 coiled. The singular markings seen in the 

 larger valve (s) areno doubt imprints of those 

 processes ; and similar appearances are also 

 visible in valves of Strophomena rhomboida- 

 lis and Davidsonia Verneuilii, where no 

 reniform impressions exist. 



1 This species seems to have been discovered independently by Mr. Howse and Professor King. Mr. 

 Howse claims the adoption of his name on account of the two days' priority of publication. 



Productus giganteus (from Mr. Woodward's drawings). 

 A. Interior of dorsal valve. B. Interior of ventral valve, with the 

 umbo removed. C. Ideal section of both valves. D. Hinge-line 

 of dorsal valve. /. Cardinal process, a. Adductor, r. Cardinal 

 muscles, s. Hollows occupied by spiral arms. v. Reniform im- 

 pressions, b. Brachial processes, h. Hinge-area. 



