346 The American Geologist. June, looi. 
separated by a ratlu-r liroad base made up of tbe usual tbree pieces. 
The columnar base is surrounded by a distinct rim, giving a slightly 
concave surface for attachment. The radials (fork pieces) are hardly 
more than half the greatest length of the body. The interradiais 
(deltoids) are more than a third of the length of the body. The am- 
bulacra are more convex than the radial and interradial borders and 
the interambulacral areas are flat or concave and three of the four 
specimens are decidedly pentangular in cross section but this may be 
due in part to the fact that the test is very thin and the three speci- 
mens in question may be a little misshapen, due to pressure. 
There are ten elongate or slit-like spiracles and an anal opening 
with a hood but less prominent thaiT in L. aplatus. 
There is no elevation above the general surface at the tops of the 
radials as in L. opinatus but the ornamentation is the same as in that 
species (fine longitudinal lines), the cross lines of the deltoids con- 
tinuing down the sides of the ambulacra as elongate triangles on the 
radials to the very end of the ambulacra. The mid-interambulacral 
triangular areas of the radials are crossed longitudinally by fine lines. 
The type specimen is 7'-j mm. long and about 7 mm. wide. The 
basal rim is a little over 2 mm. wide. 
This blastoid comes from the brown, earthy layer just over 
the top of the fifth (Hvisioii of the Lower ]^)UrHng'toii Hmestone 
and is associated with L. aplatiis, Aorocrimis wachsimithi , 
Agaricocriinis pkvwconvcrsus and Cacfocriiiiis springcn. 
Hart's and I'ratt's Quarries, Louisiana, Mo. 
An average specimen of Lophoblastus conoideus is about 
4 mm. in length In- 4 mm in breadth. A large specimen 6mm. 
in length l)v 4'2mm. in breadth. A small specimen 25^mm. in 
length by 3mm. in br.eadth. 
The species of this genus at present known are, 
Lophoblastus iuopiiiolus. Lower Burlington limestone. 
Lophohlasiiis aplatiis, near top of Lower Burlington 
limestone. 
Lophoblastus coiioiilciis, top o\ Choteau limestone. 
Lophoblastus iiiargiuitlus, top of Lower Burlington 
limestone. 
Loplioblastus rocutcri, Kinderhook or Lower Chouteau 
limestone. 
Lophoblastus ( ?) ncglcctiis. Lower Burlington limestone. 
The other group embraces three already described species 
and a new one here figured and described for the first time. 
Grauatocriuus uuigiiibasis was defined in the October, 1895 
number of the Amkrican Geologist, G. piriformis in the Aug- 
