110 
Kirtley F, Mather 
ECHINOIDEA 
ARCHAEOCIDARIDM 
Genus ARCHAEOCIDARIS M’Coy 
Archaeocidaris sp. 
Plate II, figure 10. 
The echinoidea are represented in the Morrow collections by 
three of the spines which are characteristic of members of this 
genus. The spines are slender, elongate, circular in cross-sec- 
tion, with an articulating facet at the lower end, and ornamented 
by exceedingly fine, closely spaced, longitudinal striations which 
are visible only with the aid of a hand lens. Their specific rela- 
tions are not apparent. 
A single, much-worn echinoid plate bearing an articulation 
facet for the attachment of a spine is present in the collection 
from Station 296. It presumably belongs to the same species 
as the spines. 
Horizon and locality. Brentwood limestone : near Fayetteville, 
Arkansas (Station 147). Morrow formation: near Ft. Gibson, 
Oklahoma (Station 296). 
9 
BRYOZOA 
FISTULIPORID^ 
Genus FISTULIPORA M’Coy 
Fistulipora sp. 
Plate\ IV, figures 1, 2. 
The genus Fistulipora is represented in the Morrow collections 
by a number of fragmentary specimens whose specific relation- 
ships are not known with certainty. The zoaria are irregularly 
curved, laminar expansions composed of superimposed layers of 
zooecia and with a strongly wrinkled epitheca over the basal 
surfaces. The upper surfaces of the zoaria are marked by incon- 
spicuous maculae of irregular shape and small size occurring at 
intervals of 4 or 5 mm. The apertures display various outlines 
depending upon the degree of preservation of the lunarium which 
when little worn is prominent and high. The interstitial space 
is filled with vesicles of differing sizes and in one or more series. 
Horizon and. locality. Hale formation: East Mountain, Fay- 
etteville, Arkansas (Station 136). Brentwood limestone: near 
