CEPHALOPODA. 469 



This species has no analogous forms in the New York formations. It may 

 be compared with Goniatites tuber culoso-costatus, d'A. and de V., as illustrated by 

 the Doctors SAndberger in Verstein. des Rhein. Schichtensystems in Nassau, pi. 1, 

 fig. 1 ; pi. 8, fig. 2. 



Formation and locality. In the Chemung group, near Owego, N. Y. 



Goniatites Chemungensis, var. equicostatus. 



PLATE LXIX, FIG 10. 



■''m flirnuinijni.'iU, var. equicotftatus, Hall. Descriptions of New Species of Goniatidae, p. 3. 1874. 



" " " " Twenty-seventh Rep. State Mus. Nat. Hist., p. 135. 1875- 



" " " " " Illustrations of Devonian Fossils: Cephalopoda, pi. 69, 



fig. 10. 1876. 



This variety was indicated chiefly on account of the uninterrupted and more 

 prominent annulations crossing the volutions, which are more closely arranged, 

 being about as four or five to three in the typical specimen. The exterior 

 volution is more slender, and there is a ridge or carina extending along the 

 middle of the lateral face, connecting the annulations. 



The umbilicus is wide, but the inner volutions are not preserved. The septa 

 and suture-lines are very imperfectly preserved, and it is only possible to say 

 that the septa describe numerous small lobes and saddles which are similar to 

 those of the typical form, but which cannot be described in detail owing to the 

 imperfection of the specimen. 



Surface-markings undetermined. 



Formation and locality. The specimen was found in a bowlder of arenaceous 

 Bhale containing several species of Brachiopoda, which indicate its origin to be 

 from the lower beds of the Chemung group. 



The following species are from the Goniatite limestone of Rockford, Indiana ; 

 and having been originally described in the Thirteenth Report on the N. Y. State 

 Cabinet of Natural History, in 1860, are here introduced for comparison with 

 those of the New York formations : 



