8TANT0N.] 



S0LENID2E. 115 



Sioux river, is closely related to this species, though probably dis- 

 tinct. 



Locality and position. — In the Pugnellus sandstone on Williams 

 creek and other places in Huerfano park, Colorado, where about forty 

 specimens were collected, and near the base of the cretaceous section at 

 Coalville, Utah. 



Genus PHAEELLA Gray. 



Pharella? pealei Meek. 



PI. xxv, Figs. 12 and 13. 



rharellaf pealei Meek, 1873, Ann. Kept. U. S. Geol. Sur. Terr, for 1872, p. 406;— 

 White, 1880, idem for 1878, p. 21, PL 11, Figs. 6a, b. 



Original description: 



" Shell elongate-oblong, or subrhombic,the length being about twice 

 and a half the height, rather compressed; anterior margin slightly 

 sinuous just in advance of the beaks above, and somewhat narrowly 

 rounded below this faint sinuosity; posterior margin truncated, with a 

 convex outline, very obliquely backward and downward, from the poste- 

 rior extremity of the hinge to the prominent and very narrowly rounded 

 or angular posterior basal extremity; hinge-line proper apparently 

 comparatively short, and not forming any angularity of outline at its 

 connection with the sloping posterior dorsal margin; beaks rising a 

 little above the hinge margin, but rather depressed and placed about 

 one-fifth the entire length of the valves from the anterior margin; 

 basal margin long, slightly sinuous along most of its length; posterior 

 dorsal slopes rather prominently rounded from the beaks obliquely to 

 the posterior basal extremity. Surface only showing obscure lines of 

 growth. 



"Length, 1.20 inches; height, 0.48 inch; convexity, 0.28 inch. 



"Knowing nothing of the hinge of this shell, I only refer it pro- 

 visionally to Pharella. It does not seem to have had the extremities 

 gaping as in that genus; but the specimen has evidently been acci- 

 dentally compressed, and this may have given the valves the appearance 

 of being closed. In general appearance it resembles Solcn guerangeri 

 d'Orbigny, which seems to belong to the genus Pharella. Our shell, 

 however, evidently differs from d'Orbigny's specifically, at least, in not 

 having the posterior margins of its valves near so abruptly truncated, 

 but rounding and sloping forward gradually into the dorsal outline 

 above. Possibly I should call it Modiola pealei. 



"Locality and position. — Missouri river, below Gallatin, Montana, 

 Cretaceous." 



