60 PALZONTOLOY OF NEW-YORK. 
95. 4. ENDOCERAS GEMELLIPARUM (7. sp.). 
Pu. XIX. Figs. 1 a, d. 
Teretely conical, somewhat rapidly tapering ; siphuncle lateral ; septa moderately 
convex, distant; surface? 
This fragment is of large size, being four and a half inches in diameter. It is remarkable 
for presenting, enclosed within the siphuncle, two embryo tubes, which in themselves show 
some lines of septa indicating their tendency to perfection. 
The apices of both these tubes, as in all cases of single embryo tubes, are directed 
towards the apex of the parent shell. One of them is slightly bent on one side, and covered 
with stony matter. 
Fig. 1 a. External view of the fragment. 
Fig. 1 4. Transverse section of the smaller extremity, showing the siphuncle tube which joins the 
external margin; within which are shown sections of the two embryo tubes. 
Fig. 1 c. Longitudinal section of the specimen, d and e being the two enclosed tubes, one of them 
partially covered with stony matter. 
Position and locality. In the Black-river limestone at Henderson’s Bay, Jefferson county. 
96. 10. ORTHOCERAS FUSIFORME (x. sp.). 
Pu. XX. Fig. 1. 
Elongated, gradually tapering ; outer chamber deep, gradually contracting towards the 
mouth, giving a fusiform aspect to the specimen ; septa approximate ; siphuncle excentric. 
This species presents the peculiar character of contracting towards the aperture, at about 
the same rate that it diminishes from the last septum in the opposite direction. The siphuncle 
is a large apparently even cylindrical tube. Two specimens only have been observed, both 
of which are from the base of the Black-river limestone, near its junction with the Birdseye. 
This species possesses a character which I have observed in some others, namely, that of 
having several of the last septa, and the final one especially, more closely arranged than 
the others. 
Locality. Watertown, Jefferson county ; Valley of the Mohawk, Herkimer county, 
