SPECIES OF MUECHISONIA. 



627 



band on the body-whorl is also nodulose, the surface of the shell is 

 plicated, and the keels bounding the sinual band are somewhat 

 undulating, as in M. Humboldtiana. In 1843, de Koninck (' Descr. 

 des Anim. Eoss. du Terr. Carb. de la Belgique,' p. 414) considered 

 this shell identical with a Devonian one figured and described by 

 A. d'Archiac and E. de Verneuil as M. angulata (' Trans. Geol. Soc' 

 2nd ser. vol. ii. p. 356, pi. xxxii. fig. 6) ; but in 1883, ' Faune 

 du Calc. Carb. de la Belgique,' p. 25, he says he considers them 

 to be distinct species. 



This shell bears a strong resemblance to the Devonian Phuroto- 

 maria angulata of Sandberger (' Die Yersteinerungen des Rheinis- 

 chen Schichtensy stems in Nassau,' p. 204, pi. xxiv. fig. 19). 



I am not aware of its having been described as British before. 



There are four specimens of this species in the Woodwardian 

 Museum. The length of one (PI. XXIY. fig. 6), consisting of eight 

 whorls, is 21 millim., width of body- whorl 13 millim., height of 

 body-whorl 9 millim. A portion of a larger shell (PI. XXIY. fig. 7), 

 consisting of three whorls, has a length of 21 millim. ; the width 

 of the body-whorl is 14 millim. ; height of body-whorl 15 millim. 

 The other two specimens are much smaller. 



Locality. Settle. 



Formation. Mountain Limestone. 



In the Museum of Practical Geology there are three very small 

 specimens, which are of about the same size as the smallest I saw 

 in the Brussels Museum. The length of that figured on PL XXIY. 

 fig. 8 is 7 millim., width of body-whorl nearly 4 millim. It is on 

 the same piece of rock as Pleurotomaria Griffithii, de Kon. 



Locality. Abergele. 



Formation. Mountain Limestone. 



The other two specimens in this Museum are from the Mountain 

 Limestone of Narrowdale and the Great Ormes Head. 



MlJKCHISONTA PYKAMIDATA, Sp. nOV. (PL XXIY. fig. 9.) 



Shell elongated, whorls angular, gradually increasing. Only four 

 whorls and a portion of a fifth are preserved ; there would probably 

 be ten or twelve if the shell were entire. There is a prominent 

 rounded keel situated about two thirds down each whorl, which 

 evidently represents the sinual band, though no lines of growth are 

 preserved on it. These lines curve backwards to it above and slightly 

 forward again below ; they are fine and faint. The surface of the 

 whorls both above and below the band is slightly concave, and the 

 base is convex. The form of the mouth and columella is unknown, 

 as the base is broken. The lower part of the whorl is covered with 

 fine spiral threads, thus disposed : — immediately below the band is a 

 deep groove, then a strong thread, three or four finer ones, another 

 strong thread which is about midway between the band and the 

 suture, below this there are two or three fine ones on the upper 

 whorls, but they are more numerous on the base, which is covered 

 with them. These spiral lines are slightly beaded • they are 

 probably rendered so by the crossing of the lines of growth. Above 



