18 



tricose below : sutures narrow, linear and impressed : body-whorl, 

 including the basal portion of the expanded outer lip, about one half 

 the entire length : surface marked with minute strife of growth which 

 become rather strongly marked just behind the outer lip. 



Dimensions of the most perfect specimen, — length, eleven milli- 

 metres ; breadth, four and a half mm. ; length of body-whorl, including 

 the basal or anterior end of the outer lip, six m.m. 



Hespeler, T. C. Weston, 1867. Two immature specimens with the 

 test preserved, one of unusually large size. Edge Mills, Durham, 

 abundant : Mr. J. Townsend. 



HoLOPEA Gracia. Billings. 

 Plate 3, fig. 4. 



Holopea Gracia Billings. Palseozoic Fossils, Vol. 1, p- 159. 

 Not Holopea Gracia, Mcholson. (As of Billings). Eep. on the Pal. of the Prov. 

 of Ontario, 1875, p. 72, pi. 3, fig 17. 



The type of this species, which is a mere cast of the interior, and 

 which from not having been figured appears to have been misunder- 

 stood, is represented on Plate 3. Two large specimens of a Holopea 

 with the test preserved, which are almost certainly referable to S. 

 Gracia, have recently been collected at Durham by Mr. J. Townsend. 

 These, if correctly identified, shew, (1) that the species attained much 

 larger dimensions than the type now figured ; (2) that when the shell 

 is preserved the umbilicus is completely closed; (3) that the surface 

 markings consist of crowded and oblique raised strise, which curve 

 somewhat convexly backwards above the middle of the body-whorl, 

 and concavely as well as more abruptly backwards at the base. In 

 one of the Durham specimens, too, the apex of the spire is remarkably 

 obtuse. 



Ctclonema sulcatum. Hall. 

 Plate 3, fig. 5. 



Cyclomena sulcata, Hall. Pal. N. York, Vol. 2, p. 347, pi. 84, figs. 1, la-i. 



This species was originally characterized by Prof. Hall from 

 exfoliated casts, but the fine specimen collected by Mi-. Townsend at 

 Durham, and represented on Plate 3, has most of the test preserved 

 on the last vohition. The lower half of the body-whorl is marked by 

 nine revolving raised ridges which are rather narrower than the spaces 

 between them, These ridges are mggt prominent around the narrow 



