MOLLUSCA. 779 



Volutoderma intermedia Whitfield. 



Plate XCII., Pig. 3. 



1892. Volutoderma intermedia Wliitf., Pal. N. J., vol. .2 

 Monog. U. S. G. S., vol. 18), p. 184, pi. 23, figs. 



14-15- 

 1905. Volutoderm,a interm,edia Johns., Proc. Acad. Nat. Sci. 

 Phil. (1905), p. 25. 



Description. — "Shell of medium size, elongate ovate in out- 

 line, with a moderately elevated spire and ventricose volutions, 

 the last one o^f which forms the greater bulk of the shell and 

 is most ventricose above the middle. Volutions three tO' four 

 in number and rapidly increasing in size. Aperture semilunate, 

 •oblique, nearly straight on the inner side, forming a little more 

 than half of the entire length of the shell as shown in the cast. 

 •Columella marked by twO' or three strong, oblique, nearly equi- 

 distant plications; outer surface of the shell unknown. The 

 inner surface of the volutions in one of the casts, which would 

 preserve the markings of the volution within it where any 

 existed, is entirely smooth, indicating a smooth shell ; but another 

 iragment, which appears tO' belong tO' the species, has the sur- 

 face closely lirated with markings of numerous vertical folds 

 which have formed nodes at the junction of the two sets. It also 

 shows three columellar folds, as does the smooth one. The last 

 one has been an old shell, much thickened, as indicated by the 

 great space between the coils of the cast, while the other which 

 bears the markings has been smaller and very much thinner in 

 substance. So we may readily suppose that the shell possessed 

 both sets of markings in its perfect condition." (Whitfield.) 



Remarks. — This species has not been met with in the recent 

 ■collections of the Survey. It differs from both V. biplicata and 

 V. abboitii in the greater height of its spire; in the ventricosity 

 of its outer volution it approaches more closely to the former, 

 but in the number of folds upon the columella it resembles the 

 latter. 



Formation and locality. — Manasquan marl, near Vincentown 

 (Whitfield). 



Geographic distribution. — New Jersey. 



