20 



narrowly iimbilicated. It seems most probable that the latter was the 

 case, but that the umbilical pit or cavity was too narrow to expose any 

 portion of the inner whorls. 



BUOMPIIALUS MACROLINEATOS, Whitfield. 



Plate 3, flg. 6. 



MMomphalus inacrolineatus, Whitfield. Ann. Eep. Geol. Surv. Wise, for 1877, p. 82. 



GeoL Wise, vol. 4, p. 294, pi. 18, figs. 5 and 6. 



Blora, T. 0. Weston, ISGT. Durham, Mr. J. Townsend. Two specimens, 

 which appear to belong to the same species, were collected by Mr. E. 

 Bell in the Upper Silurian Eocks of the Bale des Chaleurs, in 1862, one 

 at L'Anse d. la Barbe, and the other at L'Anse ^ la Vieille. 



The types of Euomphalus macrolineatus from Wisconsin arc described 

 as being " subdiscoidal, with a depressed convex spire," and the under 

 side of its shell is said to be unknown. Not being able to decide 

 positively, from description and figures alone, whether the Canadian 

 specimens were specifically identical with that species or not, the 

 nearly perfect example figured on plate 3 was sent to Prof. Whitfield 

 for examination, who kindly reports on it as follows : "I can see no 

 real difference between this and H. macrolineatus. The ribs are a little 

 more distant, but not enough to be specific. My specimens were both 

 impressions of the exterior, and much flattened, so that I considered it 

 a Euomphalus. Tour specimens differ from true Cyclonema in the 

 aperture and umbilicus." To the writer, these latter appear to be 

 exactly congeneric with the Cyclonema sulcatum of Hall, which, how- 

 ever, may not be a true Cyclonema. 



The characters of well-preserved and undistorted Canadian specimens 

 which are here identified with E. macrolineatus on Prof. Whitfield's 

 authority, may be thus defined. Shell tui-binate, a little broader than 

 high, composed of about three volutions, which increase very rapidly 

 in size : last whorl but one somewhat depressed above and laterally 

 depressed below the broadly rounded shoulder, in such a manner as to 

 give the shell a rather step-shaped outline : body-whorl occupying two 

 thirds or more than one half the total height, — depressed above, inflated 

 and ventricose below : umbilicus deep but narrow, its width being less 

 than one fourth of the diameter of the base : aperture nearly circular, 

 lip thin and simple. Surface marked by numerous, narrow, elevated 

 revolving ridges, which are crossed by crowded and oblique strife of 

 growth. On the upper and outer part of the body-whorl, the three 

 revolving ridges nearest to the suture are comparatively wide apart, 

 and are separated by shallowly concave grooves about four times as 



