174 BRITISH CARBONIFEROUS BRACHIOPODA. 



by from ten to sixteen regular broad, sub-equal, transverse ridges, obtusely angulated in 

 the middle, each having three or four rows of spines disposed exactly as in P.punctatus proper. 

 Dorsal valve slightly concave, and ornamented as in the opposite one. Length 8, width 7 

 lines. 



Professor M'Coy states, in his work on the Palaeozoic fossils, that " this species is inter- 

 mediate in all its characters between P. punctata and P . fimbriata, but is perfectly distinct 

 from both as a species. It agrees with the former in the numerous, instead of single rows of 

 spinules on each concentric band, while it differs from it, and agrees with P. fimbriata 

 in the elongato-ovate form, absence of mesial furrow, and very great gibbosity of the ventral 

 valve, differing, however, from it in the smaller size, greater number of concentric bands in 

 a given space at the same distance from the beak, and in having several rows of minute 

 punctures, instead of a single row of elongate tubercules on each band." 



Both P. punctatus and P. elegans occur in many of the same localities. In England 

 they are abundant in almost every locality where Carboniferous Brachiopoda have been 

 found, such as in Derbyshire ; abundantly also in the Craven district ; near Bolland ; in shale 

 and limestone at Settle, in Yorkshire ; in dark Carboniferous limestone at Lowick, 

 Northumberland ; at Kendal, Westmoreland ; Poolwash and Ronaldsway, Isle of Man, &c. 

 In Scotland it occurs abundantly in the Carboniferous limestone and shale of Lanark- 

 shire, Renfrewshire, Ayrshire, Buteshire, Dumbartonshire, Stirlingshire, Haddingtonshire, 

 and Pifeshire. In Ireland, in Calciferous slate and limestone at Lisnapaste, Millecent, 

 Tankardstown, Bruckless, Cornacarrow, &c. On the Continent of Europe it is also com- 

 mon at Vise, Lives, Namur, &c, in Belgium ; in the valley of Prikcha, at Kosatchi-Datchi, 

 &c, in Russia. In America it abounds in several localities, such as Zanesville (Ohio), 

 Eddyville (Kentucky), and in coal measures throughout the western states, &c. 



Productus Keyserlingianus, De Kon. PI. XXXIV, figs. 15, 16. 



Productus actjleatus, De Koninck. Descrip. des Anim. foss. du Terrain Carb. de Bel- 

 gique, pi. x, fig. 8 "< b - c (not Martin), 1843. 

 — keyserlingianus, De Koninck. Mon. du genre Productus, pi. xiv, fig. 6 a — d, 



1S47. 

 _ _ M'Coy, British Carb. Foss., p. 466, 1855. 



Spec. Char. Shell small, subrectangular, or rotundato-quadrate ; hinge-line slightly 

 exceeding the average breadth of the shell. Ventral valve very gibbous, sometimes rather 

 geniculated, and feebly depressed along the middle; beak small, and not overlying the 

 hinge-line except at its attenuated extremity ; ears small, slightly produced, and well 

 defined. Surface traversed by numerous concentric lines of growth, as well as by a few 

 wrinkles on the ears ; a variable number of comparatively large spine-tubercles being like- 

 wise arranged somewhat in quincunx over the visceral portion of the valve. Dorsal valve 



