80 PALEOIJfXOLUGY OF NEW JERSEY. 



TURBINELLID^. 

 Genus TURBIJSTELLA Lamarck. 



TURBINEKLA ? PARVA. 



Plate IX, Figs. 4-6. 



TurhineUa parva Gabb: Proc. Acad. Nat. Sci., PMla., 1860, p. 94, PI. il, Fig. 3; 

 Synopsis, p. 86; Meek, Check List Cret. and Jur. Foss., p. 21; Geol. Surv. 

 New Jersey, 1868, p. 730. 



Shell, as known from the type specimen, the only individual cast seen, 

 is quite small, measuring scarcely more than half an inch in height by 

 about five-eighths of an inch in transverse diameter^ but is evidently either 

 young or only the inner portions of a much larger specimen; form turbi- 

 nate, rapaform, being largest near the top of the volution and rapidly 

 attenuated below; spire very low, not flat; volutions not more than three 

 in the specimen (the inner one and a half of those destroyed), flattened or 

 nearly so on the upper surface; aperture very large, proportionally higher 

 than wide and oblique ; columella strong, marked by three distinct plica- 

 tions or folds, the two upper ones a little above the lower third of the 

 aperture, equal in strength and near together; the other one below, larger 

 and more distant but not so sharply defined as those above; volutions 

 marked by sinuous vertical folds of considerable strength, indicated on the 

 top of the volution, but more strongly marked on the periphery and below, 

 being strongly bent backward in crossing the largest part of the whorl. 



The generic relations of this solitary cast are obscure or rather compli- 

 cated. It has the general form of a Pyropsis, and the columellar folds of a 

 TurhineUa, while the surface undulations diff'er from species of either of 

 those genera. It is very evident to the observer that it is either very young 

 in growth, or a cast of only the inner portion of a shell, the outer part not 

 having been filled with sediment before being dissoh^ed and removed by 

 the action of the water or other agent. However, the surface markings 

 and columellar folds, together with the form of the volution, will determine 

 its identity very readily when found, and they certainly characterize it as a 

 valid species, if not an undescribed genus. 



