No. 89.] 



101 



13 



GONIATITES OWENI, Var. PARALLELA. 



Fig. 13, 14. Specimen showing the smaller umbilicus, and the septa produced. 



Geological formation and locality. In strata of the age of the Hamilton group 

 of New-York; at Rockford, Indiana. 



GONIATITES ROTATORIUS ? 



G. rotatorius : Db Koninck, Carb,Fossilcs de Belgique, page 565, plate 50, fig. 1. 

 [ See Note at the end of this paper.] 

 15 



This species, from the 

 same locality as the prece- 

 ding, has been identified 

 with the European form. In 

 the absence of European 

 specimens, I have only 

 means of comparison with 

 figures, and am unable to 

 point out specific differences. 

 In general form of shell, 

 and proportions of volu- 

 tions, this fossil does not 

 greatly differ from G. pa- 

 tersoni j but the presence 

 of a large umbilicus, and 

 more complicated septa in 

 that one, are distinguishing 

 features. 



The accompanying dia- 

 gram will suffice for com- 

 parison with the preceding 

 species. 



GONIATITKS ROTATORIUS. 



Fig. 15. Outline of the shell and direction of the septa. 



