DESCRIPTIONS OF SPECIES. 303 



if constant, would satisfactority differentiate the Kinderhook from the Genevieve 

 species, but at the same time Ev.. aUirostris is so rare a form that the limits of its 

 variation can scarcely be said to be known. 



JEu. uwosteri closely resembles Eu. marcyi^ but it is in even more close agreement 

 with Eu. aUirostris. Its general shape is more elongate than in Shumard's rotund 

 species; the ventral beak is more slender, though it can not be described as more 

 erect; the ribs are somewhat coarser than is common in Eu. marcyi, but they are not 

 without parallel in. fossils referable to that species. There is present a sinus, a char- 

 acter which! have as yet not observed in the Genevieve form. 



Comparing it with Eu. aUirostris as represented b}- Weller's figures and discrip- 

 tion, Eu. woosteri is found to agree very closely in size, though the shape is some- 

 what more broadly ovate. The beak seems to be almost equally acute, but is prob- 

 ably more strongly incurved. The ribs are a little finer and slightl}^ greater in num- 

 ber. There is a sinus but no strong median furrow. It seems highly probable that 

 Eu. woosteri is a synonym of Eu. aUirostris., but I retain both names awaiting further 

 evidence. 



White compares this species with Retzia idah., evidently a slip for Retzia {Sus- 

 tedia) mormon i. There can be no doubt that Eu. uwosteri is distinct from the latter 

 species. 



The f ormf rom the San Juan region of Colorado and from the Yellowstone National 

 Park, which I have identified with Eu. verneuiliana, differs from Eu. woosteri in 

 being smaller, with finer striae, and, so far as is known, in lacking a sinus. 



In the Leadville district (at station 2.375) was found a fossil wJiich seems to be a 

 retzioid brachiopod. It i5 an imperfect external cast of one valve, in which onlj^ the 

 impressions of rigid strife are pi-esented to view, the finer ornamentation, if any 

 existed, having been lost. It is larger and more numerously striated than Ilustedia 

 morinoni, and seems to be rather of the Eumetria type. It appears to present the 

 general characters of Eu. luoosterl, and though slightly smaller than the type speci- 

 men, and with ribs somewhat coarser and more broadly rounded, it appears, like it, 

 to have had a sinus, faint indications of which are still retained. 



On the whole, it is probable that this shell is an Eumetria and closelj' related to 

 Eumetria vjoosterl, to which I have provisionallj' referred it, but its relations with 

 Eu. inarcyi and Eu. aUirostris are also close. 



Locality and horizon. — Leadville district (station 2375); Leadville limestone. 



Pebbles of Millsap limestone in the Red Beds conglomerate, Larimer County (station 



2364). 



Eumetria maecyi Shumard? 



1852. Terehratula serpentina. Owen (not de Koninck), Geol. Surv. Wisconsin, Iowa, and Minnesota, 

 pi. .3A, fig. 13. (See specimens in U. S. Nat. Mus. Cat. Invert. Fosa., 17955.) 

 Carboniferous: Skunk River, Iowa. 



