154 Annals of the Carnegie Museum. 



nearly straight line between lateral saddles, while the inner suture of 

 Jonioceras shows a deep internal lobe between two saddles. Both 

 Tornoceras crebriseptum and Tornoceras douglassi show the internal 

 lobe, which is somewhat tongue-shaped in 7. douglassi and rather 

 broadly V-shaped in T". crebriseptum. 



Description. — Shell discoidal, compressed, involute, the narrow 

 umbilicus open at all stages of growth. The sides of the shell are 

 flattened, the venter rounded. The surface is marked by distant, nearly 

 straight ridges which run from the umbilicus diagonally forward across 

 the shell and turn very slightly backward on the venter. No complete 

 specimen has been observed, the largest portion of the living chamber 



Fig. 4. Tornoceras crebriseptum Raymond. Outline drawing to show sutures. 

 Natural size. 



Fig. 5. Tornoceras sp. Outline of one of the specimens in which the normal 

 course of the sutures is reversed. Natual size. 



SO far seen consisting of half a volution. The course of the suture is 

 shown by the figure. 



Locality. — This species is common in the red shale of the Upper 

 Devonian at Three Forks, Montana. 



Tornoceras sp. 



(Plate VIII, figure 4.) 



This species is represented by only two specimens, which indicate 

 a shell of the same size and shape as the preceding species, but the 

 course of the suture line is exactly reversed. Where in the pre- 

 vious species there were saddles, in this species there are lobes. 

 Even the V-shaped lobe of Tornoceras crebriseptum is a V-shaped 

 saddle in this species. This is a very peculiar condition among the 

 goniatites, ventral saddles being developed only among the chloichoan- 

 itic ammonites. The small number of specimens having this peculiar 

 form at once leads to the suspicion that this reversed position of the 

 septa is an abnormal condition. With so little material at hand and 

 what there is preserved in such refractory minerals, it is not possible 



