Weno and Pawpaw Formations 83 



lobe is narrow, very tall, and trifid, with the central point strongly de- 

 veloped. The second lateral lobe is broad, nearly the same height as the 

 siphonal lobe, its breadth being about six tenths that of the first saddle, 

 and is bifid with each lobule split into rounded tips. The third lobe is 

 twice as broad as tall and is obscurely split into four rounded divisions. 

 The first saddle is large, subquadrate in outline and deeply bifid; each 

 division is split by a lobule into two unequal bifid components. The second 

 saddle is bifid. The third saddle, which lies on the umbilical wall, is 

 wide and low. 



Fig. 7. Scaphites hilli Adkins and Winton, young individual, showing the last five 

 sutures, camera lucida drawing, x 10. The fossil is figured on PL 2, figs. 3-4. 



A comparison of the mature suture of the type with juvenile suture 

 stages is represented in figure 7. This individual differs from the type 

 in many ways ; it is less obese and its coils increase less rapidly ; its rib- 

 bing is possibly coarser; its first lateral saddle is shallow and very wide 

 and is split by a shallow lobule, whereas it is tall, narrow and split by a 

 deep lobule in the type of S. hilli; the two have the same horizon and 

 range and are apparently connected by intergrades. The situation is 

 somewhat similar to that of Scaphites aequalis and S. obliquus, and until 

 further material is available, I would refer this form to S. hitti. This 

 suture is seen to be simpler and to lack the finer divisions of saddles and 

 lobes seen in figure 6. The lobes on both individuals are, however, bifid. 



