312 
PALAEONTOLOGY OF NEW YORK. 
Orthoceras anguis, n. sp. 
PLATE LXXXIX, FIG. 9. 
Shell straight, slender, regularly and gradually enlarging. Transverse section 
unknown. The apical angle in a specimen much compressed is 5^°. 
Chamber of habitation, septa and siphuncle not observed. Air-chambers 
regular, having a depth of four mm. near the chamber of habitation, where 
the diameter of the tube is more than twenty mm. Sutures straight and 
horizontal. 
Test not preserved. Surface marked by regular transverse, lamellose, 
subimbricating strise, which become more crowded toward the apex, and of 
which there are nine in the space of five mm., where the tube has a diameter 
of about ten mm. Near the chamber of habitation the transverse lines 
become elevated into irregular ridges, with very fine intermediate strise. 
The internal mould retains the impression of the transverse markings. 
This species is distinguished from the associated forms by the marked 
characters of the surface ornamentation. O. aulax of the Hamilton, possessing 
similar general characters, has the strirn more rounded and distant. 
Formation and locality. From the shales of the Chemung group, Cascadilla 
creek, Ithaca, N. Y. 
Orthoceras palmatum, n. sp. 
PLATE XC, FIGS. 9, 10. 
Shell straight, regularly and gradually enlarging. Transverse section subcir¬ 
cular or very broadly elliptical. Apical angle about 7°. Initial extremity 
unknown. 
Chamber of habitation not observed. Air-chambers regular, with a depth 
of nine mm. where the tube has a diameter of thirty mm. 
Septa having a concavity equal to the depth of the chambers, with a distinct 
areola around the insertion of the siphuncle, and a broad flabellate or palmate 
expansion, extending to the ventral margin, which is indicated by a longitu- 
