60 DEVONIAN FAUNA. 



Size. — A fragment containing three whorls, measures 9 mm. long, and 5 mm. 

 wide. 



Locality. — One specimen is in the Porter Collection from Pilton ; and one in my 

 Collection from Pouch Bridge. Phillips records it from Brushford and South 

 Petherwyn. 



Bemarhs. — When describing M. turbiiiata, Schlot., from South Devon, I was 

 unable to find the specimen which Phillips figured in his ' Pal. Foss.' under the 

 name of M. angulata, Ph., and it then appeared to me that it might very probably 

 be a crushed or contorted specimen of Schlotheim's most variable shell. Since 

 then, however, I have obtained specimens which exactly agree with Phillips's figure, 

 and show that it represented the true form of the shell. These prove it to be 

 undoubtedly a distinct species, distinguished by the great breadth of its rapidly 

 increasing whorls, by its sinus-band being situated very near the lower suture, 

 and by the obliquely convex shape of the whorls, as well as by its very small size. 



The sinus-band is formed of two coalesced keels, but my specimen, probably 

 from its imperfect state, does not show the lower (third) keel described by Phillips. 



Miss Donald, who, as well as Mr. J. F. Whiteaves, discusses the various shells 

 under the name M. angulata, shows that the Devonian species is distinct from the 

 two Carboniferous species to which Phillips had previously applied the same name. 

 Hence it must bear the name under which D'Orbigny long ago separated it from 

 them. 



While, however, these two references to Phillips and D'Orbigny must be 

 removed from the list of synonyms of M. turhinata, there seems no doubt that the 

 M. angulata of d'Archiac and de Verneuil, Goldfuss, and other later authors is dis- 

 tinctly a variety of Schlotheim's shell, and has nothing to do with the present 

 form. 



2. MuRCHisoNiA, sp. Plate VI, fig. 15. 



Size. — Height 18 mm., width 9 mm. 



Locality. — An obscure cast from Baggy Point is in the Museum of Practical 

 Geology. 



Bemarhs. — The above-named specimen appears to me to be quite distinct from 

 M. anglica. It is much larger, its whorls are much narrower, and the sinus-band 

 seems only slightly below the centre of the whorls. It thus is much more like 

 M. turhinata, and perhaps may be the cast of one of the varieties of that shell ; 

 but it is in much too imperfect a condition to make it safe to refer it to it 

 without further evidence. 



