BULIvETIN 31 184 



Posterior half of the surface, wkh six radiating ribs, the stronger the 

 more posterior they are. They alternate with smaller radiating ribs, which 

 do not cover the umbonial part. Anterior half of the surface covered with 

 numerous radiating ribs ; its umbonial part is covered by strong concentric 

 ribs, which terminate abruptly at the first radiating rib of the posterior 

 half. Wautubbee. 



We believe multiornata and prima have been regarded as 

 very distinct and figured so on account of the very few speci- 

 mens knovi^n. There seems to be no definite number of strong 

 ribs posteriorly nor is the anterior without indications of ribs. 

 Again, the secondary, inter-ribbing, varies in strength. 



It is evident that the figured type of multiornata is only a 

 fragment of the umbonal part and does not show the outline cor- 

 rectly at all if it is really a Cardiomya. See fig. 19 for a photo 

 of a specimen from the type locality and fig. 20 for a fragment of 

 the same species from St. Maurice with more strongly differen- 

 tiated sculpturing anteriorly and posteriorly. I^ this the four 

 posterior radii are strongly marked while the anterior is weakly 

 marked . 



Cuspidaria attenuata Aldrich, PI, 55, Fig. 21 



Necera alternata A.\6i. , Bull, i, Geol. Surv. Ala., 1886, p. 38, (pi. 6, 



fig. 15, as attenuata, lapsus penncs). 

 C. attenuataDall, Trans. Wag., Ill, 1903, p. 1505. 



Aldrich's original description. — Shell small, moderately rotund, cov- 

 ered with very fine concentric lines ; rostrum short, obtuse, rounded on top 

 and angulated on dorsal margin ; lines of growth becoming lamellar on its 

 surface. Hinge line and dorsal line of rostrum straight. Cartilage pit 

 minute, narrow, oblique and close under the beak. 



Locality. — Lisbon, Ala. 



We have found no specimens corresponding to this descrip- 

 tion. In outline and marking it is wonderfully like some 

 of the Buhrstone Ledas. 



Since the name alternata is preoccupied for this genus by 

 d'Orbigny's species, Dall proposes, quite properly, to make use of 

 Aldrich's name, accidentally used on the explanation of the 

 plate, for this species. 



