329 



Shell oval-giobulose, thin, not pearly, imperforate ; aperture 

 large, oblique; columella thin, truncated anteriorly ; basal margin 

 of aperture insinuated. 



The genus may be described as an imperforate Eunaticiiia, or 

 a Sigaretus, with a sinuated front margin, and stands in relation 

 to it as Protoma does to Turritella. The non-perlaceous test 

 removes it from the neighbourhood of StomateJJa. 



Heligmope Dennanti, xpec. nor. pi. vii., figs. S-Snt. 



Shell rather thin, oval, convex [or somewhat depressed-orbicu- 

 lar] ; spire moderately prominent [or depressed]. Whorls four 

 and a-half, suture more or less concealed by the adpressed reflec- 

 tion from the anterior whorl. Ornament of slightly elevated, 

 rounded, spiral ribs, about ten on body- whorl [sometimes the 

 spiral ribs are almost obsolete], narrower than the flatly concave 

 furrows, crossed by close-set lamelliform stride, which become 

 wider apart and more distinctly lamellar with the decreasing 

 revolution of the spire. 



Aperture oblique, oblong-oval [or semicircular] ; outer lip 

 acute, crenulated by the spiral ribs ; columella cylindric, thinly 

 reflected posteriorly and adherent over the umbilical area ; the 

 lamellae of the back intersect the sinus-band. 



The words included in parentheses in the foregoing diagnosis 

 refer to the majority of the specimens obtained from Hallett's 

 Cove, and thus markedly differ from the figured specimens which 

 I select as types and with which all the Muddy Creek specimens 

 agree ; though from the former locality I have a fairly typical 

 specimen, otherwise I should have been disposed to regard the 

 depressed form as a distinct species. 



Dimensions, — Length, 32 ; width, 27 "5 ; height and width of 

 aperture, 25 and 16. 



Localities. — Miocene : Muddy Creek, Victoria, and Hallett's 

 Cove, St. Vincent Gulf 



This species was first brought to my notice by Mr. J. Dennant, 

 who kindly forwarded me the figured examples, after whom it is 

 named. 



FAMILY HIPP0NYCID.5]. 



Gkn'us Hippoxyx. 

 Hipponyx antiquatus, Lin. 

 H. foliacea, Quoy and Gaimard, Voy. Astrolabe, vol. III., 

 p. 439, pi. 72, figs. 41-45. 



A C ajndns-VikQ shell with concentric laminations and radial 

 threads. 



Habitat. — Eocene and Miocene : Muddy Creek ! Recent : 

 Australia, Polynesia, c^-^c. 



