27 



striations, which are insinuated convexly bacliwards both above and 

 below towards and to the band. The shell increases very slowly in 

 breadth ; thus, in a specimen three inches and a quarter in length, 

 which has between seven and eight of the whorls preserved, the great- 

 est diameter at the smaller end is eleven millimetres, while that of the 

 larger end, close to the aperture, is only twenty-five. 



Prof Whitfield, who has examined the specimens from which figure 

 5 on plate 4 was drawn, and compared it with Prof. Hall's types, thus 

 expresses his opinion on the former. " This shell is intermediate be- 

 tween M. turritiformis and M. longispira, Hall. The apical angle is more 

 acute than that of M. turritiformis, while the angle of the volution is 

 here central and on that one is at the base of the volution. Com- 

 pared with M. longispira the rate of increase in the diameter is about 

 the same, also the angle on the whorl, but the length of the volutions 

 in your shell is a little greater than in that species. One or two other 

 specimens would probably unite Hall's two species as one." 



MURCHISONIA CONRADI, Hall. 



Plate 4, fig. 6. 



MurchiBonia Conradi, Hall. 18th Eegents' Keport, p. 344, pi. 15 (6.) fig. 19. 



Three neai-ly perfect and well preserved specimens of a MurcMsonia 

 which should probably be regarded as a mere local variety of the above 

 named species, have been collected at Blora by T. 0. Weston and D. 

 Boyle, one of which is represented on plate 4. They differ chiefly from 

 the Wisconsin type of M. Conradi, as figm-ed by Prof. Hall, in not being 

 nearly as slender in their proportions, and in the blunter and less pro- 

 minent carination of their whorls. 



MURCHISONIA MAOROSPIRA, Hall. 

 Plate 4, figs. 7 and 7a. 



MurcMsonia macrospira, Hall. Palseont. N. Y., Vol. II., p. 346, pi. 83, fig. 5. 



This species was described from a mould of the interior of the shell 

 obtained at Gait, Ont.,a gutta-percha cast of which has been forwarded 

 to the writer by Prof Whitfield. As stated by Prof. Hall, the type 

 specimen shews "the impression of four and a part of the fifth volu- 

 tion." A similar but in some i-espects more perfect mould from the 

 same locality, which shews the impress of eight volutions, was collected 

 by Mr. A. Murray in 185Y, a gutta-percha cast of which is represented 

 by figure 7 of plate 4. The original of figure ta on the same plate is a 



