170 TRANSACTIONS OF THE WAGNER FREE 



to the tip of the spire, marking the conclusion of its growth ; Orthaidax 

 while very young has the whorls gradually ascending upon the normal juve- 

 nile spire by such an expansion, which, when developed, is continuous, en- 

 veloping the whole spire, coiling round and round it as the whorls grow, and 

 completely concealing the whole of the spire, nothing but the outside of the 

 last whorl being visible in an adult specimen. 



Orthaulax pugnax Heilprin. 

 Plate 8, figures 5, 8. 

 Wagneria pugnax Heilprin, Trans. Wagner Inst. i. p. 105, pi. 15, figs. 36, 36 a, 1887. 



Tampa silex-beds at Ballast Point (Lower Miocene). 



No perfect specimen of this species has yet been found. The restoration 

 of the outer lip and anterior end in the figures was made by following the in- 

 dications of the incremental lines on the siliceous pseudomorph. They are 

 probably not far from the truth, but this awaits confirmation. The thin outer 

 lip is almost always broken ; out of more than a hundred specimens of the 

 Chipola Orthmdax only two, and those not adult, showed the form of the 

 outer lip. It has not the anterior sinus found in Strombus near the canal. The 

 anterior end was probably recurved somewhat. In a perfect specimen the 

 whole spire would be covered by the posterior prolongation of the outer 

 whorl, and the channel from the posterior commissure of the aperture would 

 run to or nearly to the apex of the spire. None of the fragments I have seen 

 are sufficiently near the Santo Domingo species to render it likely that they 

 are the same. 0. inornata appears to be much more slender and elongate, 

 and with a more elevated and conical spire. There is always a heavy callus 

 on the body in front of the post-apertural channel. In the very young the 

 spire is shorter than in 0. Gabbi, reversing the conditions of the adult. 



Orthaulax Gabbi n. s. 

 Plate 12, figures 5, 5 a, 5 b. 



Lower Miocene bed of Alum Bluff, and Chipola beds, W. Florida. 



Shell large, solid, many-whorled ; in the very young (Fig. 5) smooth and 

 polished, except for incremental lines and a few faintly impressed spiral lines 

 anteriorly ; nucleus small, polished, glassy, not differentiated from the rest of 

 the shell ; early whorls with a very distinct, not channelled suture ; the whorl 

 in front of it slightly turrited ; each whorl after the third has three slightly 

 elevated, narrow, rounded varices, somewhat irregularly spaced, so that they 

 do not follow each other continuously down the slope of the spire; about the 

 end of the eighth whorl the posterior edge of the outside whorl begins to be 

 prolonged backward more and more as the shell grows, so that the suture 

 thus formed makes an irregular spiral line ascending the spire over the ante- 

 cedent whorls until by about the tenth turn the whole of the spire is en- 

 veloped, as well as any barnacles, vermetus, or other semiparasitic growth 



