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CRETACEOUS BRACHIOPODA. 69 



Messrs. Judd and Keeping in the Middle Neocomian or Tealby series, at Acre House, in 

 Lincolnshire. The specimens figured are in the Museum of the School of Mines, London, 

 and the Woodwardian Museum at Cambridge. 



In the 'Annals and Magazine of Natural History' for December, 1862, I figured in 

 pi. xxiv of that periodical a specimen of Rhynchonella, stated to have been found by 

 Mr. R. Dawson in Upper Greensand (?) at Cruden, Aberdeenshire, which much resembles 

 in external appearance the shell under description. 



93. Rhynchonella speetonensis, Bav. Sup., PI. VIII, figs. 32, 32#, 32(5, 32c. 



Spec. Char. Shell somewhat sub-trigonal, as wide as or wider than long, greatest 

 breadth posteriorly. Dorsal valve convex, with a wide, angular, mesial fold. In profile 

 the valve forms a rising convex curve to about two thirds of its length, when it bends 

 again upwards, so that the most elevated portion of the valve is close to the front. 

 Ventral valve slightly convex, of small depth, but forming in profile a strong convex 

 curve. Sinus large, deep, and almost pointed at its extremity ; front line W-shaped, 

 but with the lateral branches shortened ; beak small, very obtuse, and incurved ; foramen 

 minute, margined by a narrow deltidinm. Surface of each valve marked by about thirty 

 rounded radiating ribs, which assume a somewhat larger appearance as they approach the 

 frontal portion of the mesial fold and sinus. They are also closely crossed by concentric 

 lines of growth. 



Length 9, width 8, depth 6 lines. 



05s. This is a well marked species, remarkable on account of its general shape, and 

 the upward curve of its tapering mesial fold, in which respect it bears some resemblance 

 to Bh. varians. The fold also acquires a rather sudden increase in breadth at its 

 anterior termination. 



Position and Locality. Several specimens of this shell were obtained by Mr. 

 Leckenby from the Speeton Clay (Neocomian) ; and an exactly similar shell occurs in 

 the Hilsthon, Elligser Brinke Schist (Middle Neocomian), at Elligser Brinke, near 

 Hanover. German specimens have sometimes been confounded with Bh. varians, 

 Roemer. 



