MIOCENE MOLLUSCA AND CRUSTACEA, ay 
I have not been able to compare these New Jersey specimens with 
authentic specimens of Nucula obliqua of Say, so can not say positively 
wherein it differs. The figures given by Mr. Conrad of that species would 
answer equally well for many of the larger individuals of this one, and I 
presume it may be from those figures that Mr. Heilprin made the identifica- 
tion cited above. Mr. Conrad remarks under his description of N. obliqua, 
in his Miocene Fossils, p.57, that it may be a variety of the recent N. pror- 
ima, which, judging from his figures, I should think more than probable. 
Localities: It occurs in fair numbers at Shiloh, Jericho, and near Bridge- 
ton, Ne J. 
genus YOLDIA Moller. 
YOLDIA LIMATULA. 
Plate vu, figs. 11 and 12. 
Nucula limatula Say: Am. Conch., Pl. x11; Tuomey and Holmes Pliocene Foss. 8. Car., 
p. 52, Pl. xvi, Fig. 3; Conrad, Mioc. Foss., p. 57, Pl. xxx, fig. 4. 
? Nucula levis Say: Jour. Acad. Nat. Sci., Ist ser., vol. 4. p. 141, Pl. x, fig. 5. 
? Yoldia levis (Say) Conrad: Proc. Acad. Nat. Sci., Phil., 1862, p. 581; Meek, Check 
List Miocene Foss., p. 5. 
Yoldia limatula (Say’s sp.) Heilprin, Tert. Geol. U. S., p. 8; Proe. Acad. Nat. Sei. 
Phil., 1887, pp. 397, 398, and 402. 
The specimens of Yoldia which are found in the Miocene marls of New 
Jersey present to me too many similarities and too few variations from the 
living species, Y. limatula of Say, to be considered as specifically distinct, 
or even as a variety. I have not seen any specimens of it which present 
quite the features of the hinge line shown in Mr. Say’s figures of Nucula 
levis,’ from any of the American localities, the pectination always termi- 
nating much earlier than there represented. Still that may bean error of 
Say’s illustration only, and as the feature is not mentioned in his descrip- 
tion, it must remain in uncertainty. The only differences which I can find 
between the New Jersey fossil specimens and the recent ones of the same 
size, from along the coast near New Jersey, are, that in the fossil form the 
valves are perhaps a little more convex; a trifle more slender posteriorly 
and a very little more recurved than in the living ones. These I do not 
iy g 
1 Vol. 4, Ist series of the Jour, Acad, Nat. Sci. Phil, 
