i8i St. Maurice and Claiborne Pelecypoda i8i 



pect. The semi-silicified condition of the shell may hav^e oblit- 

 erated the original nacre of this form, but the various other dif- 

 ferences make it worth while to call this at least a new variet}^ 

 australina (figs. 6-8). It is the first mid-Eocene specimen de- 

 .scribed from the Gulf region to show general form and markings 

 of exterior and the characteristice interior. 



It is not unlikely that, as Dall suggests. Lea's claiboriievsis 

 is the same as other Eocene forms since described. But of this 

 fact we still have no proof. This offers a splendid instance of 

 the poor policy of giving specific 'names to mere fragments of 

 shells. Lea's figure is sufficient to show that the genus occurs 

 in the Claiborne sand but it shows nothing else. 



Type of collar di. — Texas Univ. Museum. 



Type of australina. — Cornell Univ. Pal. Museum. 



Horizoyi. — St. Maurice Eocene. 



Spedme7is figured.— T'he^ tjpe from Texas, intermediate 

 forms from the ba.se of Claiborne bluff ; the type of australina 

 from the Orangeburg District, S. C. 



Localities. — As abov^e; also at St. Maurice, La. 



Verticordia (Haliris) mississippiensis Dall, PI. 55, Fig. 9 



V. (//. ) mississippiensis Dall, Trans. Wag., Ill, 1900, p. 1198, pi. 42, 

 fig. I, p. 1510. 



DalVs original description. — Shell rounded, triangular, inflated, 

 with very high involute prosoccelous beaks ; sculpture with about thirty- 

 three narrow, angular radial ribs, uniformly distributed and with about 

 equal interspaces, the entire surface closely and minutely granulose ; the 

 granules are more or less arranged in radial lines ; basal margin arcuate, 

 produced towards the middle, serrate by the sculpture, nymphs strong ; in- 

 terior brilliantly pearly and very much disposed to scale off. 



Lon. 5.5, alt, 5.0, diam. about 6 mm. 



This shell, external, looks like a minute Pecchiolia. The pearly sub- 

 stance is so friable that it is hardly safe to attempt to describe the hinge, all 

 the specimens being more or less defective. There is no lunule. The shell 

 is much heavier than the Bowden species and more pearly. 



Eocene of the Wautubbee Hills, Clark Co., Miss. ; Burns. 



Our collection have afforded no specimen of this interesting 

 form. 



