Orthoo. 



548 



Orthoceras duseri, continued. 

 ture of the surface of the shell,'as seen,]wheii]well2preserved, 

 under a lens ; surface appears smooth to the nakedWe,'^except 



Y-Vt 



z\z 



slightly raised edges of septa ; network evidently not produced 

 by the growth of any bryozoon ; raised line runs the whole 

 length of one side of the shell. Somewhat like the Anticosti 

 0. sieboldi^ but has three times as many septa. — Waynesville, 

 0. Hudson river slate. III b, 



Orthoceras elegantulum, Dawson. Acadian Geology, 



1868, page 605. fig. 213, with a portion 

 magnified ; a beautiful species of Cepha- 

 lopod shell, closely resembling 0, per- 

 elegans^ Salter (of the English Low, Lud- 

 low formation), cylindrical, slightly flat- 

 Daw, tened; septa very convex, one twentieth 

 of an inch apart ; siphuncle central ; raised rings covered with 

 hardly visible transverse strias (16 to a line) which under the 

 lens appear as their sharp parallel curved ridges, with finely 

 granultited intervals. Arisaig, N. Scotia. Yf 



