134 



Dimensions 

 &c. of the 

 valves. 



Size. Ventral valve, length 11 mm. ; width 8 mm. ; depth, 1^ mm. 

 The dorsal valve is 2 mm., shorter than the ventral. 



Horizon and locality. Dark purplish gray sandstones of E. 26, at 

 Dugald Brook, Esjcasonie, N.S. Not rare. 



The following table gives measurements of valves from this horizon : 

 VALVES of Lingulepis longinervis from Assise E. 2 b. 



This species is remarkable for the long large callus of the dorsal valve, 

 and for the prolonged beak of the ventral valve. The average distance 

 of the visceral callus of the dorsal from the front of that valve is only one- 

 eighth of the valve's length. As the laterals of this valve also come far 

 forward it may be assumed that the visceral cavity is unusually large. 



Obolus coelatu.y Volb. sp.* presents somewhat similar appearances in 

 the dorsal valve, but its centrals are not nearly so far advanced. L. (0.) 

 acutangula, Roem.f has poinos of resemblance in the ventral valve, especi- 

 ally in the prolonged beak, and oblique striae on the hinge area. 



* Uber die Brachiopoden Obolus & Lingulella, Mem. Acad. Imp. d. Sci. St. Petersb., 

 viii, ser. vol. iv, No. 2, pi. ii, figs. 21c. and 22c. 



t Cambrian Brachiopoda, Obolus & Lingulella, U.S. Nat. Mus. Proc. vol. xxi, pL 

 xxvii, fig. 6. 



