153 Annals of the Carnegie Museum. 



present species differs in being distinctly umbilicate in the adult stage. 

 Tornoceras hicosiatum (Hall) differs from T. dotiglassi in having a 

 broad and flattened venter, and in the direction of the surface markings. 



The suture of Tornoceras peracutum (Hall) has very much more 

 pronounced lobes and saddles than that of T. doi/glassi, and Tornoceras 

 rliysum Clarke has very much stronger surface markings than the 

 species from Montana. These are the more striking differences, but a 

 close comparison shows many other differences in the course of the 

 suture, the whorl section, and the ornamentation. 



This species is named for Mr. Earl Douglass, who discovered the 

 fauna here described. 



Locality. — This species is quite common in the white blocky shale 



and in the red fissile shale of the Upper Devonian at Three Forks, 



Montana. 



EXPLANATION OF PLATES. 



Plate IIL 



I, 2, 3. Catnarottfchia coutracta IlalL Three views of an individual from the 

 green shale. X 2- 



4, 5- The same species. A cast from the red shale. X 2. 



6, 7. The same species. A small specimen from tte green shale. X 2- 



8, 9. Leiorhynchiis jiiesaroslale Hall. Two views of a specimen from the red 

 shale. X 2. 



10. Spirifer disjumtiis Sowerby. A small specimen from the red shale. X 2- 



II, 12. Spirifer pin oneiisis yietk. Two views of a specimen from the red shale. 



X2. 



13! 14) 15- Ainboicclia ^regaria Hall. Three views of a specimen from the red 

 shale. X 2. 



16. Cleiothyridi7ia devonica Raymond. A portion of the surface enlarged to show 

 the ragged edges of the lamellre from which the spines have been broken, and, in one 

 corner, the spines themselves flattened against the shell. X 4- 



17. The same species. A specimen showing imperfectly the spiral supports of 

 the Ijrachia. X 2- 



Plate IV. 



I, 2, 3. Cleiolhyridina devonica Raymond. Three views of a specimen from the 

 green shale. X 2. 



4, 5, 6. The same species. A more nearly circular individual. X 2. 



7, 8. The same species. A somewhat larger individual, with a rather small 

 sinus. X 2. 



9, 10, II. The same species. Three views of another specimen. X 2. 



Plate V. 



I, 2, 3. Loxoptcria holzapfeli Raymond. Three views of a specimen, showing 

 the relative convexity of the valves and the radial striations of the left valve. X 2. 



