170 DR G. W. LEE ON 



Another specimen, 1 1 mm. long, is partly broken, but shows both valves in apposition ; 

 the maximum distance between the two valves is 5 mm. 



The general appearance of the shell is very much like that of Prodnctus youngianus 

 Davidson, a shell which differs from the present one in having a very concave brachial 

 valve closely following the curves of the pedicle-valve ; besides, the brachial valve of 

 Productus youngianus is ornamented by ribs, the place of which is taken here by pits. 

 The nature of the ornamentation on the ears and cardinal slopes can also serve to dis- 

 tinguish it from Productus youngianus. 



The Devonian Productus dissimilis de Koninck,* is remarkably like Productus 

 brucei as regards the ornamentation of the pedicle-valve, but it is a less elongate shell, 

 with a differently ornamented brachial valve. 



Productus sp. indet. 



A specifically indeterminable fragment exhibits the ribbing typical of Productus 

 scabriculus (Martin). 



Productus cherneyensis sp. nov. (PI. II. figs. 37-376.) 



No specimens showing both valves in apposition are at hand, but the pedicle- valve 

 described here is sufficiently characterised to merit a distinct appellation. It is semi- 

 circular, measuring 17 mm. in length and 19 mm. in width. The visceral portion is high 

 and narrow ; the ears are well defined and the beak is much incurved, overlying the 

 hinge-line. The surface is ornamented with ten broad concentric folds bearing thick, 

 rounded tubercles separated by wide intervals. Between the folds, numerous concentric 

 growth-lines are visible to the naked eye. The shell-substance is very thin. 



Two small specimens, 5 mm. long, show the same characters, the thick tubercles 

 being very pronounced for such small shells. 



This species probably belongs to the group of Productus fimbriatus J. Sowerby, 

 but it differs from most of its members in having a narrower visceral cavity, and fewer 

 tubercles, which are moreover rounded, not elongate as in Productus fimbriatus. These 

 characters are well shown in a species which Dr A. Vaughan provisionally describes as 

 Productus cf. fimbriatus,^ with the remark that it probably represents a link between 

 the fimbriate and the aculeate Producti. Productus cf. fimbriatus may possibly be 

 identical with the present one, but the specimen figured by Dr Vaughan is more elongate 

 than the Cape Cherney form. 



Productus elegans M'Coy. (PI. IT. figs. 38-386.) 



M'Coy, British Palaeozoic Fossils, 1855, p. 460, pi. iii.H, fig. 4. 

 This is the most abundantly represented Productus in the collection, and it is 

 undistinguishable from its British representatives. One specimen, showing part of both 



* Monor/raphie des Genres Productus et Chonetes, p. 147, pi. xvi. fig. 5. 

 t Quart. Jour. Geol. Soc, 1906, p. 308, pi. xxx. fig. 6. 



