66 ORDOVICIAN AND SILURIAN BELLEROPHONTACEA. 



from Moberg and Grbnwall's species ; the shell is asymmetrical, which is often the 

 case in Gymbularia, as Perner points out. But the distinguishing feature of 

 Cymbularia when compared with Bellerojphon seems to be in the mouth, the lateral 

 cdocs of which are infolded instead of expanded outwards and simple, as I have 

 already pointed out. This oral character is not determinable in G. carinata, hence 

 the doubt as to its generic position. 



3. Cymbularia carinata (Sow.), var. Plate X, figs. 13, 14. 



1878. BeUeroplion carinatus, Sowerby, Salter, Cat. Camb. Silur. Foss. Mus. Pract. Geol , p. 78. 



Varietal Characters. — Shell involute, composed of 3 — 4 whorls, somewhat 

 compressed, as high as wide or rather higher than wide, subtriangular in section, 

 with gently convex sides, subangular dorsum and traces of slight keel. Umbilicus 

 open, rather deep, about one fourth the height of the shell in diameter, partly 

 exposing inner whorls ; umbilical slopes steep. Outer whorl increasing rather 

 rapidly in height to mouth, with long narrow dorsal median slit extending about 

 half the length of the whorl. Slit-band and surface ornamentation unknown. 



Dimensions. — Height of shell, 19 mm.; height of mouth, 10 mm. 



Horhun — Upper Llandovery. 



Localities. — Bogmine, Shelve, Shropshire; Eastnor Park, W. Malvern; ('win 

 Dwr, Llandovery [G. 21038]. 



Remarks. — Only internal casts of this shell are preserved, and no external 

 impressions show the surface characters. There are five specimens ['28062, 

 28064 — 67] from Bogmine and one from Eastnor Park in the Jermyn Street 

 Museum in this condition, and one in the British Museum [G. 21038], and it is 

 from these that the above description has been drawn up. The shell is certainly 

 referable to the genus Cymbularia, but it is not identical with Sowerby's B. 

 carinatus, as it has been labelled, being more swollen and less compressed, 

 but probably it may be regarded as a variety of it. 



4. Cymbularia drummuckensis, sp. now Plate X, figs. 15 — 19. 



Specific Characters. — Shell lenticular, somewhat inflated centrally, thickest at 

 umbilicus, composed of few whorls, completely involute. Whorls tectiform, 

 carinate, subtriangular in cross-section, with dorsum more or less sharply 

 angulated and occasionally weakly trilobed towards mouth ; sides gently convex, 

 but somewhat flattened towards mouth ; outer whorl completely enveloping 

 inner whorls and very slowly increasing in height. Umbilicus subcentral, 

 completely closed by callosities. Mouth subtriangular, not suddenly expanded, 



