ORTMANN : TERTIARY INVERTEBRATES. I 7 1 



Philippi compares this species (veneficus) with T. magus L. (Pliocene 

 and Recent, Europe), and indeed, this is the only relation with any other 

 known form, but it is very remote. A little closer is the affinity of T. 

 magus with the next species, as we shall see below. 



103. GlBBULA DALLI V. Ihering. 

 PI. XXXI, Fig. 9"'. 



1897 duUi v - Ihering, in: Rev. Mus. Paul., v. 2, p. 272, pi. 3, f. i, pi. 



4, f- 13- 

 1897 G.fracta v. Ihering, ibid., p. 273, pi. 3, f. 2. 



1900 G. dalli Ortmann, in: Amer. Journ. Sci., v. 10, p. 380. 



Shell conical, broader than high, widely umbilicated. Whorls convex, 

 especially in the upper part, near the suture. Last whorl obtusely cari- 

 nated on the periphery. Surface ornamented with revolving striae, and 

 oblique, tubercular, radial ribs near the suture. The latter are sometimes 

 short, and more like tubercles, in other cases they are more elongated, 

 extending almost to the middle of the upper (exposed) part of the whorls, 

 Revolving striae very unequal, 5 to 6 larger ones are found in the region 

 of the tubercles, with intermediate finer ones ; the rest, toward the periph- 

 ery, are fine. Very often, and especially in the young shell, between the 

 tubercles and the peripheral angulation (which shows partly on the upper 

 whorls above the suture), there is another revolving, blunt ridge, resemb- 

 ling the peripheral angulation. Base of shell slightly convex or flat, um- 

 bilicus deeply depressed, wide. Base with a number (7 to 8) of revolving 

 ribs, and numerous fine striae between them ; 3 to 5 of the larger ribs, 

 near the umbilicus, are distinctly granulated by fine lines radiating from 

 the umbilicus. 



Height, 17 mm; diameter, 36 mm; our largest cast measures: height, 

 about 28 mm ; diameter, 52 mm ; v. Ihering gives : height, 35 mm ; diam- 

 eter, 63 mm. 



Remarks : I regard G. fracta as the young stage of this species. The 

 only difference according to the diagnosis ; the figure does not show any 

 differences except that it is smaller is the presence of two spiral angula- 

 tions in the lower part of the upper whorls. These blunt ridges are present 

 in almost all individuals, and even those that are large and show the 

 typical character of G. dalli on the last whorl, exhibit them on the upper 



