5)0 The American Geologist. February, I89r) 
A NEW CRETACEOUS GENUS OF CLYPEASTRID/E. 
By F. \V, Cra<;in, Colorado Springs, Colo. 
The family (Jlypeastridat makes its first appearance in tlie 
upper Cretaceous, and witli forms which, so far as hitlierto 
known, are of diminutive size and l)elong to the genera Echi- 
nocjiHiiiiis and Fibvlaria. Eocene representatives of this 
family are also mainly of small size, though averaging larger 
than the Cretaceous. It is in the Miocene that large-sized 
clypeastrids, like Clijiiednter and Sen tel / a, i'lr^t become abund- 
ant, though P^ocene representatives of the former genus are 
known in Ital}^ and elsewhere. 
Tlie discovery of a large-sized clypeastrid, bearing points 
of resemblance to both Chjpeasfer and Sciitella. in the upper 
Cretaceous, is therefore of considei-able interest. 
The only known example of this clypeastrid is in the writ- 
er's private collection of Cretaceous Invertebrata. It is the 
type not only of a new species but of a new genus also; and 
these may be described as follows : 
Scutellaster. gen. nov. 
clypeastrid large, combining the flattish-convex, or discoi- 
dal, test of ScvtcUa with the pentagonal outline of Cli/peosfer \ 
disc without loop-holes or any emarginations other than shal- 
low convexities; ambulacral petals closed, or nearly so. 
Sctifellaster crelacens^ sp. nov. 
Test as large as that of a large Scufena, or that of one of 
the more moderate-sized species of C'bjjteaster, obtusely pentag- 
onal, its hight apparently about equal to, or not more than, 
one-tenth of its length ; ambulacral petals of moderate breadth, 
reaching to within a short distance of the ambitus, the un- 
paired and anterior paired petals being straight, the posterior 
paired ones slightly sinuous; breadth of a pore belt (appar- 
ently) about half that of a semiambulacrum, the part of the 
ambulacrum between the pore-belts ornamented with light- 
colored puncta (the supposed spine-scars) arranged in 
((uincunx; interambuhicral plates thick, separated by deep 
sutures that are made especiall}^ pronounced by the beveled 
borders of the plates, the adambulacral half (on distal plates, 
less than half) of each plate being crossed with slightly raised, 
parallel curved lines, which subtend the borders of the ambu- 
