38 PALEONTOLOGY OF NEW YORK. 



face ornaments do not differ materially from those in some varieties of N. buci- 

 num and N. liratus (Pal. N. Y., vol. v, pt, 2, pp. 407, 412). 



Distribution. In the shales of the Hamilton group, near Cumberland, Md. 



Nautilus parallelus. 



PLATE CXXVI, FIGS. 3-5. 



Haul elus, Hall. Fifth Ann. Rept. State Geologist. Expl. pi. (126) 11, tigs. 3-5. 18S6. 



Shell small, gradually enlarging to the aperture ; volutions not emhracing. 

 Transverse section lenticular, with acute lateral angles. 



Chamber of habitation nearly twice as long as the transverse diameter, 

 mtv gradually expanding to near the aperture, which is constricted. 



Siphuncle sub-central. 



Surface marked by fine lines of growth and by elevated longitudinal lines 

 or slender ridges, which are distant from 2 to 3 mm. 



The chamber of habitation has a length of 60 mm. on the ventral side 

 and a transverse diameter of 20 mm. at the last septum. The ventro-dorsal 

 diameter at the same point is 16 mm. 



The single imperfect specimen representing this species in the collection, 

 was recorded as doubtfully from the Chemung group, at Salamanca, N. Y. 

 The character of the rock and general appearance of the specimen do not 

 agree with other fossils obtained from that locality, but closely resemble 

 specimens from the coal measures of Ohio. It is probable that the specimen 

 was misplaced in the collections and erroneously referred to the Chemung 

 group of New Y r ork. 



Tin' species also represents a Carboniferous type of Nautilus, and is related 

 to tin- pi i us Temnocheilus, Meek, and to species classed as Gyroceras by De 

 Koninck, obtained from the Carboniferous rocks of Belgium. 



Distribution. Probably from the coal measures of Ohio. 



Nautilus (Discites) Ammonis. 



PLATE CXXV, FIG 1. 



ammonis, Hall. Pal. N. Y.. vol. v, pt. 2, p. 425. 1879. 



