Is differentiation of ribbing characteristic of all the late interior scaphite stocks? Investigate. differ in the differentiation of the ribbing. Otherwise similar in form & ornamentation. Although intermediate steps are lacking (so far), this form resembles some of late Trail-City, strongly hooked, quadrate-sectioned, multivodose types. 16. Czst labeled - loc. 21584 (USGS) Sazo Creek road 1.1 miles south of turnoff from US Hwy '16, 5 miles SE Wzsta, 14 SW1/4 SW1/4 sec.18, T.1N., R.15E., Pennington Co., S.D. - Note on label "specimen thought to resemble that of Meek, v. 9, pl.35, fig 4. called in text S. abyssinus.- this is Cobben's idea, George disagrees. So do I. Oruzment like pungens except for lateral row. 2nd finer ribs on septate part. V-1 nodes small flexuk uodes on primivics. coarse ribs Sharp change in oruzment with offset of 6F lines ventrolateral uodes Looks as if it skipped some growth