638 W. D. SMITH 



Scaphites nodosus Owen is by far the largest Scaphite of those 

 mentioned in this paper. It is, like all of the nodosus group, coarse- 

 ribbed in the neanic and ephebic stages, growing more smooth on the 

 abnormal body chamber where the coil leaves the true spiral. It 

 has strong nodes on the ventral shoulders, and sometimes also on 

 the umbilical shoulders. The form is quite robust and is remark- 

 able for its long, last body chamber which has left the whorl partly 

 and turned back on itself somewhat as in the case of Macro scaphites, 

 though not so pronounced. 



Scaphites nodosus brevis is coarse-ribbed, but shows no nodes on the 

 umbilical shoulders, and is a much smaller form, less gibbous, and just 

 beginning to leave the coil. 5. nodosus plenus is simply a very gib- 

 bous form, with about the same dimensions as brevis. Its suture in the 

 adult is somewhat different, and the nodes are not so pronounced. S. 

 nodosus quadrangularis can be distinguished from brevis only by its 

 flattened dorsum and the very small nodes on the umbilical shoulders. 



5. mullananus is slightly smaller than the others, and, as far as 

 the writer can determine, does not leave the coil at all, and possesses 

 no abnormal body chamber. Nodes are altogether lacking, the ribs 

 coarse and passing from umbilicus to umbilicus. 



The two Oregon species are very much smaller than those men- 

 tioned above, flatter, and almost devoid of ornamentation. At the 

 very end of the last coil there is a slight departure from the coil and 

 a constriction around the coil just back of the aperture. The largest 

 of these would not be more than i$ mm in diameter. Scaphites 

 condoni has a slight wrinkling or development of ribs on the side of 

 the adult coil, but no nodes. 5. inermis, on the other hand, possesses 

 a row of very small nodes on the ventral shoulder or the last coil. 

 They are both extremely thin forms. 



5. nodosus Owen, which is not shown in the plate, measures about 

 3 J inches in diameter along its longest axis; S. nodosus brevis and 

 the others, about 2 inches and less. They all have narrow umbilici. 

 This is quite the opposite from what we find in the Oregon species. 



DISTRIBUTION 



The type of this comprehensive genus was first found in Dorset- 

 shire, England, by Parkinson, 1 in the year 181 1. Scaphites, however, 



1 Parkinson, Organic Remains, Vol. Ill, p. 145, PI. X, Fig. 10. 



