INVERTEBRATE PALJSONTOLOd V. 441 



Since the foregoing remarks were originally published nearly as here 

 written, another entirely new view of the functions of these bodies, has been 

 published. (See remarks at the end of the description of the genus Scaphites 

 on page 419). 



Locality and position. — Fox Hills, Moreau and Cheyenne Rivers, Dakota; 

 from the Fox Hills group of the Upper Missouri Cretaceous series. 



Scaphites abyssinus, Morton (sp.). 



Plate 35, figs. 2, a, b, aud 4. 



Ammonites dbyssinas, Morton (1841), Jour. Acad. Nat. Sci. Philad., VIII, 209, pi. 10, rig. 4. 

 Scaphites Mandanensisl, Meek and Hayden (185C), Proceed. Acad. Nat. Sci. Philad.,* VIII, 281. 

 Scaphites abj/ssinus, Meek and Hayden (1860), ib., XII, 420. — Meek (ISG4), Smithsonian Check-List N. Am. 

 Cret. Fossils, 23. 



Shell short-oval, or subcircular, much compressed; inner volutions 

 deeply embraced within the dorsal groove of each succeeding turn; last 

 whorl flattened on the sides and periphery, having a more or less distinct 

 subnodose angle around the umbilicus, and on each side of the periphery ; 

 non-septate portion short, not widened or straightened along its upper mar- 

 gin, and deviating so little from the regular curve of the inner whorls as to 

 become but slightly disconnected from them at the aperture; umbilicus 

 rather small; aperture oval or subcordate ; surface ornamented by rather 

 distinct, straight, or slightly flexuous costse, which increase chiefly by the 

 intercalation of shorter ones between the longer, so as to number from two 

 to three times as many at the periphery as near the umbilicus ; those on (he 

 inner whorls often supporting some three or more rows of very small nodes 

 on each side, in addition to the larger series on each side of the narrow 

 flattened periphery. 



Septa divided into three or four lobes and as many sinuses on each side 



of the si phonal lobe, which is of an oblong form, being a little longer than 



wide, with two principal branches on each side, the two terminal of which are 



slender, larger than the others, nearly parallel, obscurely bifid, and provided 



with a few obtuse short digitations or crenulations ; while the lateral branches 



are short and spreading, the larger pair being merely obtusely tridentate, and 



the others simple; first lateral sinus as long as the siphonal lobe, and near 



one-fourth wider, with a nearly cpiadrangular form, and provided with two 



large unequal, irregular branches, with short, obtusely crenate subdivisions ; 



first lateral lobe a little shorter than the siphonal, and of nearly the same 

 56 H 



