264 PALEOZOIC PALEONTOLOGY. 
GASTROPODA. 
HOLOPEA ANTIQUA (Van.). 
Plate XXIV., Figs. 15-16. 
1859. Holopea antiqua Hall, Pal. N. Y., vol. IIL, p. 294, pl. 54, figs. 
2 a—b, 3 a-b. 
Description.—Shell subconical, spire elevated, with four or more 
volutions. Suture moderately impressed, the volutions regularly con- 
vex. Aperture ovate or subcircular. Surface marked by fine, trans- 
verse lines of growth. 
Remarks.—The specimens which have been referred to this species 
are all imperfect, and are usually only the internal casts. The apical 
angle of the New Jersey specimens apparently varies between 55° and 
60°, which is somewhat less than that of Hall’s illustrations of the 
species, in which it measures nearly 70°. This measurement of the 
New Jersey specimens, however, cannot be made with certainty, be- 
cause in no case is the complete spire retained. 
PTEROPODA 
TENTACULITES GYRACANTHUS (Haton). 
Plate XXIV., Figs. 19-20. 
1859. Tentaculites irregularis Hall, Pal. N. Y., vol. III., p. 187, pl. 
6, figs. 22-23. | 
1888. Tentaculites gyracanthus Hall, Pal. N. Y., vol. V., pt. IL, 
Supp. (Supp. to vol. VII.), p. 5, pl. 114, figs. 7-13. 
Description.—Shell elongate, circular in cross-section, annulate, 
gradually tapering to the apex. Annulations smooth, rounded, situated 
at irregular intervals, from one to three in the space of 1 mm.; the 
interspaces between the annulations are marked by fine, annular strie. 
In internal casts the annulations are smaller and the fine, annular 
strize are lacking from the interspaces. ’ 
