87 



few impressions of strise remaining upon the cast are not sufficient to 

 decide whether the fossil be a Loxonema or Murchisonia ; and since all 

 the Gait specimens, which are of the same age, appear to belong to Afur- 

 chisonia, I have concluded to refer this one to the same genus." All the 

 specimens from Ontario that the writer has seen are mere casts of the 

 shell, upon which no vestiges of the surface markings are preserved. Still 

 in these the general shape of the shell, with its compressed convex bub 

 evenly rounded volutions, devoid of the slightest indication of a slit band, 

 appears to the writer to be much more like that of a, Loxonema than that 

 of a Mtirchisonia. Moreover another species of Loxonema is now known 

 to occur in the Guelph formation of the province. The largest specimen of 

 L. Boydii known to the writer, when perfect, would probably have been 

 about an inch and three-quarters in height or length. The apical angle' 

 of specimens from Ontario is 24°. 



The genus Loxonema is included by Lindstrom. in the family of Euom- 

 phalidse of De Koninck on account of its insinuated growth lines like those 

 of Eiiomphalus, its solid axis and earliest " whorls filled with an organic 

 deposit of homogeneous calcite," as in that genus. On the other hand, 

 the late Dr. Paul Fischer* regarded these points of resemblance as of little 

 importance, and placed Loxonema in the Pyramidellidas and Uuomphalus 

 in the Solariidse. 



Loxonema magnum, Whitfield. Var. 

 Plate 13, fig. 2. 

 Loxonema magnum, Whiteaves. 1884. This volume, pt. 1, p. 17. 



Shell rather large, elongated, turreted, slender : apical angle about 16° 

 Volutions not less than eight and probably as many as ten when perfect, 

 the later ones moderately convex and not much broader than high, the 

 last not much larger than the one which immediately precedes it : suture 

 deeply impressed in the cast. Surface markings unknown. 



Gait, Hespeler and Elora : the specimens referred to on page 17 of the 

 first part of this volume as Loxomena magnum, Whitfield. They seem, 

 however, never to have attained to so large a size as L. magmmn, and 

 their volutions are apparently much more convex proportionately than 

 those of that species. The rate of increase of the volutions of the typical 

 L. m,agnum, is said to indicate a " length of fully eight inches for the 

 entire shell," but judging by the proportions of specimens from different 

 localities in Ontario, their entire length could scarcely have been much 

 more than five inches. Still, these supposed difierences may be more 

 apparent than real, and the writer is by no means convinced that the 

 Ontario specimens are specifically distinct from L. magnum. 



*Mantiel de Conchy liologie, &c. , p. 715. 



