468 PALEONTOLOGY OF NEW YORK. 



The largest specimens have a diameter of more than 100 mm., and the 

 smallest specimen identified with this species has a diameter of about fifty- 

 live mm. 



The Goniatites sinuosus, as originally illustrated in the Geolog. Surv. of N. Y.: 

 Rep. of Fourth Dist., included two very distinct species. In order to rectify this 

 error, I published, in 1874, a description of G. Nundaia, recognizing the species 

 ns being in part those forms which had before been included under G. sinuosus. 

 By this rectification it was intended to leave the form figured on page 245 of 

 the Geological Report as the representative of G. sinuosus. The condition of 

 preservation of the original specimen is such as to preclude a critical examina- 

 tion of the septa and other important characters, while its form and external 

 aspect are so nearly similar to G. discoideus that I am induced to unite the two 

 a^ one species. The appearance of an umbilicus in the original figure is due to 

 some adhering stone upon that part of the shell. 



The specimen, figure 11 of plate 72 is one of those originally referred to 

 G. sinuosus. It is a part of the chamber of habitation from its commencement, 

 ahd the characters of the last septum cannot be fully determined, owing to the 

 imperfect condition of the margins. Unlike the specimen just mentioned, it 

 possesses a wide umbilicus; and in the proportions of the outer chamber and 

 the position of the summit of the saddle, relatively to the dorsal and ventral 

 margins, it has the character of those forms referred to G. Nundaia, and these 

 must therefore be referred to the same species ; and since G. sinuosus has the 

 priority, the forms previously recognized as G. Nundaia will be included under 

 the original designation. It is to be remarked, however, that one of the 

 original specimens of G. sinuosus possesses some differences which are quite 

 marked, but which are apparently not of specific importance. A comparison 

 of fig. 11, pi. 72, with figs. 13-15, of pi. 70, will show that the fragment illus- 

 trated on pi. 72 has a proportionally smaller umbilicus, and more rapidly 

 enlarging tube. 



This species, in its various conditions of preservation, has much general 

 resemblanoe to G. complanatus, var. perlatus, but the volutions are less deeply 

 embracing, the septal lobes and saddles are conspicuously different, and the 



