84 PALEONTOLOGY OF NEW JERSEY. 



Geuiis KANOIA Desmoulius. 



Rangia (Perissodon) minor? 



Plate XV, flgs. 4-(i. 



Onathodon minor Ooiirad: Am. Join-. Sci., vol. 41, Isl, si-r., i.. fiO, PI. ii, fig. 14; 



Miocene Eoss., p. »i!», I'l* xxxix, fig. 6; Tuomey and ll<»]iiics, Plioc. Foss. 8. (J., 



p. !)!), PI. xxili, fig. 2. 

 Ranffia minor Ooiirad: Proc. Aca<l. Nat. Sci. I'liila., 1862, p. 57:5. 

 Rangia {Perissodon} »«i«o»- (Conrad), Meek: Check List Miocene Foss., p. 11. 



" Subtriangular, convex-depressed, inequilateral; posterior extremity 

 truncated and nearly direct; umbonal slope angulated. 



"The hinge resembles that of M. [G.] r/mi/i. The shell is proportionally 

 shorter and less ventricose, and is distinguished by the more direct posterior 

 margin." (Conrad, in Miocene Fossils.) 



I have seen Ijut a single valve (right) that I can refer to this species, 

 and I am in considerable doubt in regard to that one. The »form of the 

 shell closely resembles Mr. Conrad's figure, both in outline and convexity, 

 as in size; but ;is he has not figured the interior, and as I have not seen the 

 type, I can only judge of its internal features by the statement tliat it 

 resiimh\es Gnathodon Grai/i in this respect, which it does only very distantly. 

 Tlie specimen is of a triangular or triangularly ovate form, moderately con- 

 vex, umbonal angle 'distinct, and the .dope abrupt. The jK)sterior end is 

 slightly arcuate and the anterior rounded. Surface smooth and semipolished. 

 In tlie interior the hinge has a single thin and almost sharp central tooth, 

 with a small pit on each side. On the anterior side a moderately Avell- 

 developed lateral tooth is distinctly shown, with two supplementary teeth, 

 and also a sujiplementar}' tooth on the posterior side. These are exceed- 

 ingly thin and small, and the (h)ubling of the one on the anterior side may 

 be an accidental feature. The muscular imprints are small but distinct and 

 the pallia! sinus is wide iiiul shallow. The shell is not a. true Mactra, neither 

 is it a true Raugiii, l)ut it dilfers too nuich from the hinge features of Con- 

 rad's type of Perissodon, Gnafhndnn Groifi (zn G. dafhrodbnfn), to render it 

 entirely safe to place it in that gemis. 8o I have jjlaced it under Rangia 

 provisionally. 



Lornlifi): The s])ecimen used is from Shiloh, N. J., and belongs to th^ 

 National Muj^euiu collection. 



