152 Annals of the Carnegie Museum. 



Locality. — This species is found rather rarely in the red shale of 

 the Upper Devonian at Three Forks, Montana. 



Suborder MICROCAMPYLI Hyatt. 



Family BACTRITID^ Hyatt. . 



Genus Bactrites Sandberger. 



Bactrites nitidus sp. nov. 



(Plate VII, figures 9-12.) 



The collection contains considerable fragmentary material of a 

 species of Bactrites which appears to be much like Bactrites gracilis 

 Sandberger and B. gracilior Clarke. None of the specimens from 

 Montana retain the shell or show any trace of surface markings, and 

 for that reason, as well as because there are minor differences in the 

 casts, it has been thought wiser not to refer these forms to any 

 established species. 



Description. — The shell is subcircular in section, uncrushed speci- 

 mens being only slightly elliptical. The diameter of the shell dimin- 

 ishes so slowly that the tapering is hardly noticeable on the longest 

 specimens in the collection. The septa are oblique, sloping toward 

 the dorsum, and are gently convex. The cameras become more 

 shallow as the living chamber is approached. The largest fragment 

 shows eight cameras in a length of 18 mm. Another specimen with 

 about the same diameter has two cameras in a length of 7 mm. The 

 sutures show a slight backward curve on the sides of the shell, but are 

 nearly straight. There are only two fragments of living chambers in 

 the collection. The largest is 12 mm. in length. One of the smaller 

 specimens, 8 mm. in length, is so perfectly preserved that the cast is 

 not broken so as to show the siphonal funnels, and, in consequence, 

 the suture is entire. On this specimen may be seen faint traces of 

 oblique ridges like those with which Bactrites gracilis and B. gracilior 

 are ornamented. 



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

 Upper Devonian at Three Forks, Montana. 



Family NAUTILINID^ Hyatt. 



Genus Proloiules Karpinsky. 



Prolobites simplex sp. nov. 



(Plate VII, kigures 13, 14; Plate VIII, figures 1-3.) 



Description. — Shell plump, involute, the umbilicus becoming very 



