364 F. R. CoH-per Real — New Fossils from Haverfordicest. 



shell ornamented witli rather strong concentric growth-lines and 

 ridges on apertural lobes, and generally with one rather strong, 

 broad constriction a little inside margin of mouth ; general surface 

 of shell ornamented with a minute, regular cancellation composed of 

 equal-sized, fine, revolving strife closely placed and crossed by similar 

 transverse, slightly flexuous striae. 

 Dimensions : 



Height (average) about 20 mm. 



Diameter ,, ,, 8-10 mm. 



Horizons.— {I) Redhill Beds; (II) Slade Beds(?). 



Localities. — (I) Prendergast Place and Lane; (II) lane near 

 Crundale, and Robeston Wathen. 



Remarks. — The specimens of this shell are usually only preserved 

 as internal casts, which are generally somewhat crushed and distorted. 

 In a few instances the aperture and external ornamentation are fairly 

 well seen. It is a rather abundant fossil in the Redhill Beds, but 

 examples in anything approaching a perfect condition are rare. 



The close resemblance of this form to the well-known but 

 frequentl}' misunderstood Bellerophon bilobatns, Sow.,' is obvious, 

 and it undoubtedly belongs to the same group of species, which was 

 named Sinuites by Koken (189G),- and subsequently Frotoicarlhia 

 by Ulrich (1897) ^ in apparent ignorance of Koken's name, the 

 former choosing B. bilobatns as the type and the latter B. cancellatns, 

 Hall, which has frequently been regarded as identical. Our shells, 

 however, differ from typical examples of Sowerby's species in 

 having a more narrowly rounded back, a less subquadrate section of 

 the whorls, a less broad and less globose shell, a more rapidly 

 increasing outer whorl, and a constriction near the mouth. The 

 fine cancellation of the surface, though not mentioned or figured by 

 Sowerby in his original description of B. bilobatns, was observed by 

 McCoy * and Salter * in specimens which they attributed to that 

 species. Koken's ^ Sinnites bilobatns, mut. viacer, maj' be identical 

 with our form, but his description is too brief, and no figure has 

 been published. Portlock's B. bilobatns,'' var, compressus, is founded 

 on too crushed a specimen to determine its original shape and 

 characters. But his £. elongatns * closely resembles our Redhill 

 form in shape, though certaiidy devoid of the peculiar fine 

 Cancellation on the surface. Through the kindness of Dr. Kitchin 

 I have had access to Portlock's types, and it is much to be regi'etted 

 that they are in such a wretched state of preservation that his 

 specific names are practically worthless. Accordingly, I feel 



1 Sowerby: in Murchisou's Silur. Syst., p. 643, pi. xix, tig. 13. 



- Koken: Die Leitfossilien (Leipzig, 1896), p. 392; id., Bull. Acad. Imper. Sci. 

 St. Petersb., ser. v, vol. vii (1897), No. 2, p. 117. 



2 Ulrich: op. cit., pp. 848, 867. 



* McCoy: Syuops. Brit. Pal. Foss. Woodw. Mus. (1854), p. 309. 

 = Salter: Cat. Camb. Silur. Foss. Woodw. Mus. (1864), p. 67. 

 « Koken: Die Leitfoss., p. 393 ; id., Bull. Acad. Imper, Sci. St. Petersb., ser. v, 

 vol. viii (1897), No. 2, p. 118. 



' Portlock : op. cit., p. 397, pi. xxix, figs. 2a, 2b. 

 « Ibid., p. 397, pi. xiix, figs. 4a, 4 J. 



