JURASSIC AND TRIASSIC BRACHIOPODA. 207 



moderately deep. Surface of valves covered with from twenty-five to thirty-six sharp 

 angular ribs, of which from six to eight occupy the fold and sinus. The ribs are also 

 closely intersected by small projecting lines of growth. Two specimens measured — 



Length 7, breadth 7^, depth 5 lines (one of Tate's original Yorkshire 

 specimens). ,, 9, „ 12, ,, 7 ,, (a Banbury specimen). 



05s. — Professor Tate remarks that " this may be the species alluded to by Young 

 and Bird as Ter. \_Rh.~] depressa, Sow., which they state has nearly the same form 

 as their T. comjjressa, which is amply described by them." It cannot be denied that 

 a very close resemblance exists between it and the Cretaceous species, so close, indeed, that 

 some of the specimens could hardly be distinguished. Professor Tate considers it to 

 be a new species, but a study of more specimens is requisite to finally determine whether 

 Rh. sub-concinna and R. fodinalis are really distinct species ; some middle-sized 

 specimens of both in my collection could scarcely be separated. While looking over 

 Mr. Beesley's collection at Banbury, Professor Tate was surprised to find tha^ 

 specimens from the Am. spinatus Zone (Middle Lias) of the neighbourhood of Banbury 

 were much larger and finer than those he had collected from the Am. spinatus Zone of 

 Eston, Stapeworth, and Guisborough, in Yorkshire. 



207. Rhynchonella obsoleta, Sow. Dav., Ool. Mon., p. 90, PL XVII, figs. 1 — 5 ; 



(and Var.) Sup., PI. XXIX, fig. 4. 



This species occurs chiefly in the Great Oolite and Bradford Clay ; but a number of 

 specimens apparently undistingnishable from those occurring in the Great Oolite have 

 been met with by Mr. Darell Stephens in the Inferior Oolite of Bradford Abbas and 

 Crewkerne Station, Dorsetshire, and at some other localities. 



208. Rhynchonella sub-obsoleta, Dav. Ool. Mon., p. 91, PL XVII, fig. 14. 



Inferior Oolite Marl, Hartley Bottom. It was also found in the same formation by 

 Mr. J. F. Walker at Peak, Yorkshire Coast. 



209. Rhynchonella angulata, Sow. Dav., Ool. Mon., p. 92, PL XVII, fig. 13. 



At p. 92 of my Oolitic Monograph I described this species. Sowerby's figures of it 

 in the ' Mineral Conchology ' are not good ; but I was able to draw the original example 



