234 



thickened. No umbilicus. Surface with fine sharp backward curving 

 striae. 



This species is a variety of that group to which M. perangulata (Hall), 

 M. serrulata (Salter), M. gyrogonia (McCoy), and others belong. From 

 .the first of these it differs in having no umbilicus. The second has two 

 carinae below the angle on the body-whorl. The third, as figured by 

 McCoy, has the whorls more oblique. 



Locality and Formation. H, I, K, L, M, Table Head and Point Rich, 

 Newfoundland ; Quebec group. 



Collector. J. Richardson. 



MURCHISONIA AUGUSTINA. (N. Sp.) 



Fig. 221. 

 Fig. 221. Murchisonia dugustina. A variety of M. bdlicincta. 



Description. Shell large, with from eight to ten strongly convex 

 whorls, which are obscurely angulated, and with spiral band, jus^ below 

 the middle. Aperture sub-ovate, with indications of a canal at the lower 

 angle. The lip is free all round ; on the upper side in contact with the 

 penultimate whorl, and on the inner side with a fold which forms an 

 angular canal, and leaves open a small umbilicus. Surface with obscure 

 undulations curving backwards to the band, and probably fine striae, 

 although none can be seen on the specimens (which are silicified). The 

 band is situated on the angular part of the whorl, and appears to be 

 smooth. 



Length of a specimen of the average size from the apex to the anterior 

 angle of the aperture 3| inches ; width across the last whorl and aperture 

 about 20 lines. 



The casts of this species closely resemble, both in size and form, those 

 of M. bellicincta (Hall), so common in the Trenton, the only difference 

 being that the whorls are slightly angulated below the middle, instead of 



