:ir dllttu. ) 



tfrn\\ ii -pct-mien. Surface markings on the whole nearly the same as in C. ornatus, 

 only the transverse ridges are not confine.! to the dorsal slopes !>ut continue down- 

 wan! with a -li^'ht retral curve over the ventral slopes as well. The reticulation 

 of the surf:tr> also changes with growth in a manner not olwerved in that species. 

 Thus on the minute inner whorl the surface is almost smooth, only a few ohscure 

 revolving lines being visil.li> on this part. With the beginning f th* second turn 

 the sculpture changes abruptly to the usual style of reticulation, but for some 



.nee the tran-ver-e ime- curve backward towards the dorsal carina as in C. 

 retrormw and ' >. Tlii- retral curve, however, is soon lost so that on the 



greater part of tin- -hell they pass directly over the carina as in C. ornntns. 



The peculiarities of this beautiful shell are so obvious that comparisons are 

 quite unnecessary. It is the only species of the genus in which the whorls are not 

 in contact. 



Formation and totality. Richmond tfroiip ( the Cincinnati period, near Sprint; Valley, Minnesota, 

 where two specimens were found In aMoclatlon with (M/u'.< sutyuodrato tod IIUIIHTOUS nthi-r llrarhiopoda 

 character!/ 1 1. k 1 th>- horizon. 



CWbettm.-B. O. Ulrich 



I:TOLITS(?) DILATATIIS, n. sp. 



I I. ATE LXII. FI08. -. 



Shell 15 to 30 mm. in hight, the inner volutions unknown, the outer expanding 

 I rapidly in width, sharply carinated or alated on the sides, more obtusely upon 

 the back, transversely triangular quadrate in section; dorsal slopes flat except near 

 the prominent lateral edges where they are concave; ventral side nearly flat, with 

 a central groove probably for the reception of the dorsal carina of the inner volu- 

 tions; aperture nearly or about twice as wide as high, subtriangular, the width 

 slightly exceeding the hight of the entire shell, the outer margin with a broad, 

 centrally angular sinus, the inner lip with a small "saddle." Surface markings 

 unknown: outer part of a large cast of the interior with a few faint transverse 

 wrinkle> of growth. 



Of this remarkable species we have seen but two specimens, one, a large cast of 

 the interior, belonging to the Powers' collection of the 1 niver-ity of Wisconsin. the 

 other a smaller testiferous example collected by I-!. <> Ulrich in Minnesota. The 

 latter exhibits no signs <P f -urface markings, but this is evidently due to lark of 

 preservation. In the absenre of any knowledge of (lie superficial sculpture, the 

 generic position is somewhat doubtful. The great width of the aperture ami the 

 wing-like expansion of the lateral edges are suspicious ami possibly indicate a 



relation to Curinar , When fully known we believe it will be recopii/ed as 



.-,.-. 



