568 PBOF. E. J. GARWOOD ON THE LOWER CARBONIFEROUS [DeC. 1912^ 



Localities. — Piper-Hole Quarry, Ravenstoiiedale ; above Shap- 

 Abbey Cliff, Shap District ; under Hall-Head Farm, Kendal 

 District ; Low Meathop, Arnside District. 



liHYNCHONELLA (PuGNAX) EAWCETTENSIS, Sp. nOV. (PI. LI, figS. 2 a 



&2b.) 



Descriptiou. — General form subrhomboidal. Shell rather 

 small : an average specimen measures in length 10*5 mm., in 

 width 12 mm., and in thickness 8 mm. Apical angle = about 125°. 

 Plications extend from the beak to the anterior margin. There are 

 six plications on each side of the median fold in the brachial valve. 

 Sinus shallow, only well marked in the anterior portion of the 

 shell. The plaits in the fold are typically three in number, and are 

 usually produced slightly beyond the general margin (fig. 2 a). 



This small rhynchonellid, although belonging to the same 

 group as Pugnax phurodon, possesses marked and constant 

 characters which differentiate it from that well-known species. 

 The points of difference are : — 



1. Mature specimens have a considerably smaller size than P. 'pleurodon. 



2. It has a relatively narrow and more swollen form. 



3. The sinus is more rounded and less pronounced. 



4. There are a smaller number of plications in the sinus. 



This form resembles in man}-- respects Wi. acutirugata of L. G. 

 de Koninck.^ It differs from that species, chiefly in the general form 

 of the fold and sinus, and in the character of the apical angle. 



Horizon and localities. — Productus-globosiis Band; Semi- 

 nula-gregaria Sub- zone. Fawcett Mill, Shap District ; near Park 

 House, Eavenstonedale District; under Cunswick Scar, Kendal 

 District. 



Prodfctus globosus, sp. nov. (PI. LI, figs. 4 a & 4 h.) 



Shell small : an average specimen measures 8 or 9 mm. along 

 the hinge-line. Length of specimen, as usually preserved, from 

 umbo to anterior margin = 33 mm. 



Pedicle -valve. — General form globular, tapering rapidly to 

 the umbo. Umbonal region greatly inflated, strongly arched and 

 incurved. Hinge-line straight, and scarcely as wide as the greatest 

 width of the shell. Shell devoid of any trace of sinus, but almost 

 uniformly convex. 



Eibs very fine, thirty-five in 10 mm., measured at the middle of 

 the anterior portion of the visceral disc. In this region the ribs 

 are but slightly undulating, and the region is typically devoid of 

 intercalated ribs. In the umbonal region, just where contraction 

 takes place rapidly, there is a regular zone of fresh intercalations, 

 as shown in PI. LI, fig. 4 a. Ears covered with numerous well- 

 marked wrinkles, which are confined to these regions. There are no 

 traces of concentric lines of growth over the visceral disc. Groups 



1 ' Faune du Calcaire Carbonifere de la Belgique ' pt. vi, Ann. Mus. Roy. Hist. 

 Nat. Belg. vol. xiv (1887) pi. xvi, figs. 1-14. 



