262 MISS JANE DOKALD ON THE GENEEA [May 1 899, 



from tlie Galena, Trenton, and Black Eiver Formations of Lake 

 Winnipeg ; it is a very large shell, greatly resembling the European 

 H. insignis, Eichw. M. melaniaformis, Shum ard/ from the Calciferous 

 Group, and M.Boydii, Hall,^from the Guelph Formation, may possibly 

 also be referred here, but they are both too imperfect for certainty. 

 IJlrich & Scofield place If. io^/rmn, Hall, from the Guelph Formation, in 

 the genus Coelocaulus, but it is not well enough represented to say to 

 which genus it should be referred. As figured in ' Pal. New York,' 

 vol. ii (1852) pi. Ixxxiii, fig. 4 6, by Hall, and in Quart. Journ. 

 Geol. Sec. vol. xxxi (1875) pi. xxvi, fig. 3, by Nicholson, it closely 

 resembles H. cingulata, His., but fig. 4a of Hall has a greater spiral 

 angle. 



HoEMOTOMA Salteri, Ulrich & Scofield. (PI. XXT, figs. 7-11.) 



Sormotoma Salteri, E. 0. Uh-ich & W. H. Scofield, 1897, Einal Rep. Geol. & Nat. 

 Hist. Surv. Minn. vol. iii, pt. ii (Palfeont.) p. 1016 & pi. Ixx, figs. 44-51. 



MurcMsonia {Hormotoma) gracilis, J. W. Salter, 1859, Geol. Surv. Can. 'Canad. 

 Organ, Rem.' dec. i, p. 22 & pi. v, fig. 1 (non M. gracilis, Hall), 



Description. — Shell elongated, conical, composed of more than 

 ten whorls. Whorls increasing at a moderate rate, smooth, flat above, 

 convex below, with a slight swelling immediately beneath the 

 suture. Sinual band situated near the middle of the whorl, flat or 

 rather concave, margined by a faint raised thread or obscure keel 

 on each side. The lines of growth curve obliquely backward to the 

 band above, and still more strongly forward below, indicating a V- 

 shaped sinus of moderate depth in the position of the band. Sutures 

 deep. Aperture subovoid, produced below and slightly channelled. 

 Inner lip reflected on the body-whorl, and possibly covering a minute 

 umbilical chink. Columella somewhat thickened and arched for- 

 ward. Base convex. 



Remarks. — This species was first described by Salter, and iden- 

 tified by him with MurcMsonia gracilis. Hall. Ulrich & Scofield 

 have since pointed out that it is a larger shell with a greater spiral 

 angle, and they therefore separate it from the t3'pical M. gracilis 

 under the specific name Salteri. There are two specimens in the 

 Geological Survey Collection, Edinburgh Museum, which appear to 

 agree with this species. As they are merely casts, one cannot, 

 however, be quite certain of their identity. They are sufficiently 

 preserved to show some of the distinctive characters, namely, the 

 smooth, convex, and subangular whorls with slightly thickened 

 sutural margin, subovoid aperture, refiected inner lip, and indica- 

 tions of the flat submedian band.. In the British Museum (Nat. 

 Hist.) there are seven specimens of this species from the Trenton 

 Group, Allumette Island (G. 11489 and G. 11490), with which I 

 have compared the Scottish shells, and I find that they agree with the 

 smaller examples. The lines of growth, sinual band, and aperture 

 are best preserved on a fragment of the largest Canadian shell, which 

 is probabJy the var. nitida, Ulr. & Sco. It consists of three whorls, 



1 Rep. Geol. Surv. Missouri, 1855, p. 208 & pi. C, fig. 13. 

 ^ ' Pal. New York,' vol. ii (1852) p. 346 & pi. Ixxxiii, tig. 3. 



