85 



Sherborne and at Crewkerne Station, and has also been met 

 with, although less abundantly, at Bradford Abbas and some 

 other places. 



No. 24. BHYNCHONELLA SENTICOSA, Von Buck. Plate IV., fig. 

 20. 



TEKEBBATULA SENTICOSA, Var. Von Jluch., Tiber Tereb., 183-i. 



Shell transversely oval, wider than long; valves convex, no 

 fold in dorsal one, but a shallow sinus is present in the posterior 

 portion of the ventral valve ; beak small, acute, incurved ; fora- 

 men small ; margin line curved in front ; valves ornamented by 

 a very great number of minute longitudinal ridges, from which 

 rise a vast number of fine delicate tubular spines, covering the 

 whole surface of the shell; length ten, width eleven, depth 

 seven lines. This species does not appear to be as abundant as 

 the preceding one in the Bradford Abbas district. A few good 

 examples were found by Mr. Darell Stephens at Bradford Abbas, 

 Crewkerne Station, and near Sherborne. None of the specimens 

 of this shell, or of Rh. spinosa, had their spines preserved. 

 They usually remain in the matrix from which the specimens are 

 knocked out. 



No. 25. EHYNCHONELLA RINGENS, Herault. Plate IV., fig. 



17-18. 



TEREBRATULA RINGENS., Tiber. Von. Buck. Teiebratufa, 1834. 



Shell somewhat subpentagonal, about as wide as long, the 

 depth exceeding the length and width; the smaller or dorsal 

 valve rises abruptly from the umbo to the front, being an almost 

 perpendicular convex curve, forming a large rounded central 

 mesial fold, bent downwards at its extremity; on each of the 

 lateral portions of the valve are two, three, or four short ribs, 

 but these do not extend over the anterior half of the valve ; in 

 the larger valve the beak is small, acute, and incurved ; foramen 

 small; the mesial sinus begins to appear at a short distance 

 from the extremity of the beak, its central portion being occu- 





