158 



surface descends with a flat slope to the suture ; below the band the 

 whorls are uniformly ventricose. The last whorl appears to be about 

 two-thirds of the whole length of the shell. The band has a distinct but 

 narrow carination on its upper side. Surface nearly smooth, but, on a 

 small portion of the shell which remains, very fine striae are visible. The 

 band, as indicated in the cast, is narrow and shghtly concave. 



Length about 1 inch ; width about 8 lines ; width of the band on the 

 last whorl about | of a line. 



The surface resembles a short M. hellicincta, from which it differs in 

 the form of the whorls, by being flat above the band. The shell is thin, 

 and the band not visible on any of the whorls except the last, in the only 

 specimen collected. 



Locality and Formation. — Elora. In the Guelph formation; Middle 

 Silurian. 



Collector.— B.. Bell. 



MURCHISONIA HeRCTNA. (N. Sp.) 

 » Fig. 141. 



Description. — Conical ; apical angle about 65°; whorls 5 or 6, some- 

 what flat. Base nearly flat ; outer edge of body whorl narrowly rounded ; 

 upper side of whorls flat or very slightly concave along the middle ; the 

 spire is slightly turretted, the lower edge of each whorl projecting a little 

 over the upper edge of the one next below it. Umbilicus very small in 

 the cast, and when the shell is preserved it must be nearly if not entirely 

 closed. Surface, judging from a small portion of the shell remaining, 

 with fine strige, which curve gently backwards from the suture to the 

 lower edge of the whorl. The upper whorls appear in the cast of some of 

 the specimens, to be gently convex, instead of flat. 



Locality and Formation. — Gait. In the Guelph formation. 



Collector. — E. Billings. 



HoLOPEA Harmonia. (N. sp.) 



Fig. 142. 



Description. — Shell turbinate ; apical angle about 80°; whorls 3 or 4, 

 the last one with a wide flat band along the middle, equal to a little more 

 than one-third the whole height of the whorl ; above the band the shell 

 ascends with a gently convex or nearly flat slope to the suture. On the 

 under side the last whorl is gently convex, and the base of the shell is 

 thus somewhat flat. The upper whorls are apparently gently convex or 

 flattened, but they are not well preserved in the only specimen collected. 



