450 



WJiST INDIAN MOLL USES— SIMPSON. 



sutiiie bciii,!!,' shallow and soiiiewliat caualiciilati', with about 10 strong-, 

 revolving costa^ on the body whorl and 5 on the ])euult whorl, and 

 between these are smaller revolving lira'. The eenter of the base for 

 about two-tifths of the diameter of the shell is perfectly smooth, and 

 slightly hollowed in the umbilieal region. The upper part of the aper- 

 ture of the only specimen found is broken away, leaving only the basal 

 tooth, which is slightly compressed parallel with the outer edge of the 

 basal lip. 



Diameter 3A, height nearly 3 mm. 



Found with Xcoci/clotus bakcri and other fossil shells. 



PLEUKODONTE BOWDENIANA, luw species. 

 Plate XVI, figs. 3, 4, 5. 



Two fragments of this shell were found, .m apex with 3 whorls and 

 about one-third oi" the base of a body whorl with the aperture in perfect 

 condition. The fragment containing the nucleus shows the upper sur- 

 face of the whorls perfectly plain, the suture being only marked by an 

 elevated line ; it has a wide umbilicus and a very sharp keel. The other 

 fragment shows a rather sharply defined perii)heral keel; the a|)erture 

 is very oblique and rather compressed, with two strong teeth, which 

 are somewhat like those of P. lucerna, but are set more obliquely with 

 the aperture, the outer one being somewhat llattened on the upper ex- 

 tremity f the lip is thin, not reflected above, reflected and joined solidly 

 to the base along- its inner half, the outer basal half is free and well 

 reflected. Back of the basal lip there is a deep, somewhat oblique, 

 oval pit, corresponding exactly with the shape of the outer tooth, and 

 extending within it to its summit. The large umbilicus of the young 

 shell is completely closed by the flattened callous of the lower lip in 

 the adult. The diameter of this shell if perfect would probably be 

 about 40 mm., the height about 15 mm. It was found in company with 

 the other fossils in the Bowden beds. The basal pit behind the aper- 

 ture is a remarkable character, and I know of no other Fleiirodonte 

 which has it developed in such a manner. 



The Tltyaanophora found with the above fossils is, I believe, new, but 

 it is not in tit condition to describe or figure. 



Explanation of Plate XVI. 



Fig. 1. Xcociiclofas ( Pfuchococlilhs) haleri, new species; from above. 



Fig. 2. Xcocifclotus ( rtyvhococlilis) baJceri, new species; dorsal view. 



l"ig. 3. I'lciirodoi'te bowdeniana, new species; aperture, front view. 



Fig. 4. I'lciirodoiite bowdeniana, new species; base. 



Fig. 5. Plenrodonte bowdeniaua, new species; upper view, fragment. 



Fig. G. Liicidella cosiata, new species; front view; upper portion of outer lip broken. 



1- ig. 7. Sa'jda maxima, new sjiecies; front view. 



Fig. 8. Sa;/da maxima, new species; basal view. 



