< 



sides In tin- ca-t tin- expansion appears very abrupt )>ut doubtless it is much less 

 -.. in the shell itself. Inner lip slightly reflexed at the side*, thick centrally; outer 

 lip bn;ully and deeply sinuate. Surface markings unknown; slit long. The best 

 -.[..-mien -ecu has the following dimensions: entire hight 46 mm.; hightof aperture 

 _".' nun.; greatest width of same 33 mm.; width and hight of last volution just 

 U-hiii'l the aperture about 23 mm.; hight and width of inner end of same 5 and 8.5 

 nun. respectively; greatest diameter of umbilicus about 23 mm.; length of slit 

 about 31 mm. 



The hight in this species is relatively greater than in R frank fort ensis, which 

 we consider as more closely related than any of the other species. The aperture 

 also is less nearly triangular, the apertural margin, as seen in a side view, less 

 uniformly curved, the umbilicus larger, and the volutions more evenly rounded on 

 the back. The next species, Ji. crassa, is a more closely coiled and heavier shell, 

 having, therefore, also a smaller umbilicus. The form of the mouth and sinus is 

 also different. Casts of If. sinmlatris resemble those of the associated Salpingostoma 

 richmondensis in a remarkable degree. For comparisons see description of that species. 



Formation and locality. Richmond croup of the Cincinnati period, Richmond, Indiana. 

 CWfcrtwn.-E. O. Ulrich. 



l'.lr\XIA CRA88A, W. />. 

 I'l.ATK IAVII. KI08. 



This species, though closely resembling H. fmnkfortensis and ti. nnshv illensis in 

 many respects, will be distinguished almost at a glance by its uniformly convex 

 instead of subangular dorsum. This difference, in conjunction with a greater 

 relative width of the whorls, causes the aperture to be proportionally wider. The 

 lower lip also, though strong, has a longer slope and its surface is less convex. 

 The umbilicus is somewhat smaller and more abrupt than in H. frankfortensis, and 

 the shell more globose. 



The specimen figured has suffered considerably from maceration, the slit-band 

 and all, excepting the strongest of the surface markings, being quite obliterated. 

 On two other specimens, neither as complete as the one illustrated, there is a 

 low, yet well delined, rounded dorsal ridge, and in one this is accompanied O n each 

 side by a faint furrow, while anteriorly it terminates in an open slit about 17 mm. 

 long. Whether this dorsal ridge was originally flat or concave on the summit, and 

 bore lunul;i>. we are unable to say. Still, it is to be expected that such a condition 

 obtained on the perfect shell. As to the surface markings, what remains of them 

 indicates a sculpture similar to that shown in our figures of It. lindsleyi and /;. 

 nashvillensis. (See plate L X V I . 



