Missouri Palaeontology. — Rowley. 303 
ville, Mo. The figured specimen is from the Chouteau lime- 
stone of the former place. 
Eretmocrinus nodosus Rowley. 
Fig. 9. Side view of the body of a specimen differing somewhat 
from the type of the species. 
Eretmocrinus nodosus was figured and described in Vol. 
XXV, February, 1900, American Geologist. 
The figure on the accompanying plate is of a more elongate 
but lessi nodose specimen, occurring, however, in the same 
ht>rizon as the type. 
Base layer of the Upper Burlington limestone, Pratt's quar- 
ry, Louisiana, Mo. 
Amplexus archimediformis, n. sp. 
Fig. 10. Side view of the type specimen, natural size. 
The type specimen as it lay half imbedded in soft white 
chert, looked strikingly like the axis of an Archimedes. Owing 
to the very thin and delicate character of the frill-like expan- 
sions and the difficulty of removing the matrix without injuring 
the specimen, the fossil has been but little cleaned. The body 
is very slender, elongate, often twisted or distorted, constricted 
in places and surrounded at irregular intervals by thin, broadly 
expanded calicular-like growths. There are no external ap- 
pearances of either septa or tabulae, but it is almost certam 
from stems apparently of this species, split lengthwise, that the 
septa are merely superficial, leaving the greater part of the 
steni diameter as a cavity divided into chambers by tabulae ex- 
tending entirely across the latter, arranged like the external ex- 
pansions at irregular intervals, but not very close together. 
The calyx of the type cannot well be cleaned without de- 
stroying the outer-cup wall, but was obviously a deep funnel 
with a thin and greatly expanded outer wall, almost smooth 
both on the inside as well as on the outside, the lamellae hard- 
ly visible at the bottom of the cup around the edge of the tab- 
ula. This peculiar coral occurs about seventeen feet below the 
Orophocrinus stelliformis horizon of the Lower Burlington 
limestone at Louisiana, Mo. 
The type came from the Duff Green quarry and is from a 
white chert nodule. 
Other specimens from the Pratt and Cole quarries. 
