448 OARBONII-'EROUS FOKMATIONS AI^l) KAUNAS (IK COLORADO. 



Edmondxa MOKTONEN8I8 Geinitz? 



KSIid. AKl<irli: iiioiioiioixi.'i. Geinitu, Carb. uiui Dyas in NcliraKka, ]). 17, tali. 1, fig. 26. 

 Upper Coal Measures: Nebraska City, Nebr. 



1898. Edmondm mnrtoncnsin. Weller, U. S. Geol. Surv., Bull. No. 153, p. 243. 



Ono specimeu from Sinbads Valle}' (station 2285) is ttie only example of tliis 

 species known in our Colorado collections. It presents many points of resemblance 

 to the shell which Geinitz figures under the name of Astarte mortonensiH. It is 

 marked by strong, equally spaced lamella, whose course is straightened and sub- 

 rectilinear posteriorly. M}'' shell differs from that figured in being less elongated 

 transversely. 



Localii/y and horizon. — Dolores River region, Sinbads Valley (station 228.5); top 

 of the Hermosa formation. 



Edmondia subtruncata Meek. 



1872. Edmondia subtruncata. Meek, U. S. Geol. Surv. Nebraska, p. 215, pi. 2, fig. 7. 



Upper Coal Measures: Rock Bluff, Nebraska; Atchison, Kan.s. 



Lower Coal Measures: Illinois. 

 1895.' Edmondia subtruncata. Keyes, Missouri Geol. Surv., vol. 5, p. 127. (Date of imprint, 1894.) 



Upper Coal Measures: Kansas City, Mo. 



1899. Edmondin subtruncata ? Girty, U. S. Geol. Surv., Nineteenth Ann. Rept., i^t. 3, p. 580. 

 Upper Coal Measures: Atoka quadrangle. 



Two specimens have come to hand, one collected between Hermosa Creek and 

 Animas Valley (station 2205) and the other on the west side of Animas Valley (station 

 2204). They are unfortunately rather crushed, but seem to belong to the species above 

 cited. These are large shells with a transverse diameter of at least 43 mm. 



Locality and horizon. — San Juan region (stations 2204, 2205); upper portion of 

 the Hermosa formation. 



Edmondia? .sp. 



At station 2219, in the San Juan, occurs a rare but very interesting lamellibranch 

 shell, which is unlike any that I have met with or seen recorded from our American 

 Carboniferous faunas. Unfortunately, the five specimens in our collection are too 

 imperfect to permit its generic affinities to be ascertained. It is probably no true 

 representative of the genus Edmondia. 



In size this shell is small, having a width of about 12 mm. and a height of 

 10 mm. The shape is similar to that of an Edmondia or a Nucida. It is strongly 

 gibbous, the eccentric umbones are oblique, produced, and incurved. The general 

 shape is transverseh^ elliptical and the outline is curved. There is a strong emargi- 

 nation (of the outline) below the umbones on the side nearer the anterior end. The 

 superior margin on the other side, or hinge line, is nearly straight. It begins with 



