gl2 TE JOCKNALTORAGHOEOEN 
York Hamilton beds, and A. /amellosa, of the Burlington Lime- 
stone, though it approaches much closer to A. /amellosa than to 
A. spiviferoides. A well-preserved exfoliated specimen from the 
Chouteau limestone near Springfield, Mo., closely resembles a 
specimen of A. sfiriferoides, which is in the same condition of 
preservation, from the black calcareous layers of the Hamilton 
series of New York. 
Athyris prouti, Swallow. Though this species has never been 
figured, it is well characterized and easy of recognition. Speci- 
mens have been examined from the typical locality, and com- 
pared with those from the base of the Chouteau group, near 
Springfield, Mo., they cannot be separated. The species is not 
apt to be confused with any other American form, but it is sim- 
ilar to and possibly identical with <A. reticulata, Gosselet,’ of the 
Middle Devonian of Europe. American specimens agree closely 
with Tschernyschew’s? figures of this species from the Ural 
Mountains, and the surface ornamentation of the American form 
is identical with the European. 
Leptena rhomboidalis, Wilckins. This cosmopolitan species is 
one of the most interesting in the whole fauna. It occurs in 
all the beds of the Chouteau group and extends up into the 
Burlington Limestone. In studying its geographic and geologic 
distribution, it is found not to be recorded in the Devonian fauna 
of the west, though it does occur in Europe. It occurs 
abundantly, however, in the Lower and Middle Devonian faunas 
east of the Mississippi River. Its origin in the Chouteau fauna 
may probably be traced to the eastern Hamilton fauna. 
Orthis (Rhipidomella) michelini. L’Eveille. Although the 
subgenus Khipidomella is present in the European Devonian 
faunas, it does not occur in those of northwestern America. The 
form from which R&. michelini has its origin is R. vanuxemi, Hall, 
of the eastern Hamilton beds. Indeed, it is most doubtful 
t Spirigera (Athyris) reticulata, GOSSELET, Ann. Soc. Geol. du Nord. Vol. IV., 
p- 312, Pl. Ill., Figs. 3 a-f (1887). Spirigera reticulata, GOSSELET Equisse Geol. du 
Nord de la France; Pl. VI., Fig. 6 (1880). 
? Athyrts reticulata, Vschernyschew, Die Fauna des Mitt. und Ober Devon am des 
W. Abhange des Urals., p. 57, Tab. X, Figs. 16 a—d (1887). 
