426 UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 



third lateral sinus small and merely provided with two nearly equal terminal 

 branches, with more or less sinuous margins; third lateral lobe hardly more 

 than half as large as the second, and bearing two very short, digitate, terminal 

 divisions. Between the last-mentioned lobe and the umbilicus there is a 

 minute, tridigitate lobe, very similar to the auxiliary lobe of the third lateral 

 sinus, but smaller. 



Length, 3.13 inches; height, 2.65 inches; convexity, 1.90 inches. 



In the style of its ornamentation this species resembles our S. Warreni, 

 but it differs, however, remarkably in form and size, being much larger, 

 and proportionally very decidedly more gibbous, with a proportionally-smaller 

 umbilicus. As the septa of the type S. Warreni are yet unknown, I have 

 not had an opportunity to compare their structure with those of the form 

 under consideration; but it is probable that they will be found to present 

 differences in their details. Certainly those of the Wyoming form that I 

 now regard as only a variety of S. Warreni, are quite different. 



This and the last described species agree most nearly with division (a) 

 of the subgenus Scaphif.es, but still differ in some respects. 



Locality and position. — Same as last. Lieutenant Mullen, of the United 

 States Topographical Engineers, collector. 



Scapliitcs nodosus, var. b re vis." 



Plate 25, figs. 1, a, b, c. 



Scaphites (Ammonites?) nodosus, Owen (1652), Report Geological Survey Iowa, Wisconsin, and Minnesota, 

 580, tab. 8, fig. 4.— Meek and Hayden ( 1860), Proceed. Acad. Nat. Sci. Philad., XII, 420.— 

 Gabb (1861), Sy nop. Moll. Cret. Form., 32.— Meek (1864), Smithsonian Cbeck-List N. 

 Am. Cret. Fossils, 24. 

 Compare Scaphites compressus, Eoemer (1841), Verst. des Nordd. Kreid., 91, tab. XV, fig. 1 (not 

 d'Orbigny (1840),Pale"ont. Fr., Terr. Oct., I, 517) ; and S. constrictus, Sow#rby (sp.), 

 Min. Conch., pi. 184 a, fig. 1. 



Shell longitudinally-oval, moderately convex ; volutions generally higher 

 than convex, inner ones forming a considerable portion of the entire bulk ; 

 deflected or body-portion moderately high, but short, or only becoming 

 a little free at the aperture ; periphery rounded throughout ; umbilicus small ; 

 aperture oval-subquadrate, being higher than wide, and more or less sinuous 

 on the inner side ; surface ornamented by small, bifurcating costae, that are 

 somewhat flexuous on the sides, but become even and nearly straight on the 

 periphery; each side of body-portion also bearing near the periphery a row 



* This species (of course including all of its varieties, and the similar European types) compose 

 division (b) of the subgenus Scaphites. 



