302 American Geologist. ^^^' ^^^^ 
Both; specimens are from the top of the fourth division of 
the Lower Burlington limestone, Pratt's quarry, Louisiana, Mo. 
Schizoblastus sayi Shumard. 
Fig. 4. Ventral view of an imperfect specimen showing the exten- 
sion of the ventral covering over the ambulacral furrows of two areas. 
In fact these furrows have been covered in all five of the ambulacra 
and only recently have the roofing plates been removed as shown by 
the calcite still filling the furrows like little rods. The two areas that 
still preserve the covering show the furrow to be arched over by a 
neat little roof, the ambulacrum appearing like a blunt ridge. We 
have this same feature exhibited on two or more specimens of Oropho- 
crinus stelliformis, the roofing extending to the very ambulacral tips 
as has been the case in the specimen of sayi before us. 
The specimen came from the base of the Upper Burlington 
limestone, Pratt's quarry, Louisiana, Mo. 
Lophoblastus pentagonus, n. sp. 
Fig. 5. Basal view of the type specimen, natural size. 
Fig. 6. Ventral view of the same specimen. 
Fig. 7. Side view of the type. 
Fig. 8. Ventral view of the same specimen, four diameters. 
The three basal plates of the usual blastoid shape, form a 
low conical convexity quite half the greatest diameter of the 
body. The length of the radials is more than half the body 
length and their width is two-thirds their length. 
The interradials are long enough to be well seen on a side 
view. The pore pieces of the rather narrow ambulacra have all 
been removed from weathering, thus exposing the lancet piece, 
full length. The ambulacra are not sunken but form strong 
rounded ridges whose distal ends are so far from the radio- 
basal sutures that a basal view gives a rather strong stellate 
appearance to the fossil. The anal interradial has been re- 
moved but the anal opening was probably above medium size 
and bounded on the outside by a hood-like projection. The 
spiracles are ten rather elongate openings. The spade-like in- 
ner areas of the interradials are depressed at their centers like 
miniature finger prints. 
The surface for the attachment of the column is rather 
small and the columnar canal minute and apparently round. 
The ornamentation is probably delicate longitudinal ridges as 
in other species of the genus but our specimens are not in a 
condition to show this feature. The collection contains four 
specimens, two from Bowling Green and two from near Curry- 
