25 



body -whorl in length : volutionB six, the first, second and third ventri- 

 cose and obliquely rounded, the fourth and fifth angulated in the 

 middle : body-whorl rather obtusely angulated above the middle, 

 rounded and ventricose below : umbilicus very small in the cast and 

 probably closed altogether when the test is preserved : surface mark 

 ings unknown. 



Entire height of the specimen figured, twenty-eight millimetres : 

 height of the spire only, fifteen mm. : maximum breadth, nineteen mm. 



Hespeler, T. C. Weston, 186*7 : township of Glenelg, J. Townsend, 

 1883. 



A longer and naiTOwer shell than the preceding species, with fewer 

 and more centrally angulated whorls and a narrower umbilicus. It 

 appears to be more nearly allied to the M. Mylitta of Billings, from the 

 same formation, of which it may prove to be an extreme variety. The 

 differences between the two are as follows : — In M. Mylitta the whorls 

 are four or five, the last whorl, which is the only one that is angulated, 

 is two thirds of the entire length : in M. Sespelerensis there are six 

 whorls (or between five and six) the fourth, fifth and six of which 

 are distinctly angulated, and the body-whorl is about one half of the 

 entire length. 



MURCHISONIA C0N8TRICTA. (N. Sp.) 

 Hate 4, fig. 4. 



Shell turreted, spire long and slender, whorls numerous, probably 

 about twelve, increasing slowly in size, the earlier ones flattened or 

 faintly concave, the later ones bearing an obtuse spiral band or faint 

 angulation at a distance of three-fourths their height from the suture 

 above, and concavely constricted above the angulation : suture linear, 

 moderately impressed : last volution short, less than one third the entire 

 length, obtusely angulated a little above the middle, rather strongly 

 concave above the angulation, rounded and ventricose below: base 

 imperforate, but with a distinct groove on the inner and lower side of 

 the thickened basal portion of the columella: aperture subovate, 

 higher than wide and somewhat angular exteriorly : outer lip thin 

 and simple : test rather thin : surface markings unknown. 



■Durham, Mr. J. Townsend. A- single specimen, with eight whorls 

 and most of the test presei-ved, but with its outer surface too much 

 worn to show any of the sculpture. 



This species appears to be most readily distinguishable from M. Boylei, 

 Nicholson,* which it closely resembles in form, by the different posi- 



* Report upon the Palseontology of the Province of Ontario. 1875. Page 71, pi. 

 3, fig. 1. 



