22 
AUG. F. FOEKSTE 
Mesopalaeaster (Hemipalaeaster) schucherti sp, nov. 
Plates IV, V 
Measurements: disk imperfectly preserved; its radius, meas- 
ured from the center to the nearest part of the interbrachial arc, 
estimated as between 10 and 12.5 mm. Length of rays, meas- 
ured from the basal radial to the tip, 25 mm.; distance from 
center of disk to tip of rays estimated as between 34 and 36.5 mm. 
Ratio of the longer radius, from the center of the disk to the tip 
of the rays, compared with the shorter radius, to the nearest 
part of the interbrachial arc, between 3.4 and 3, probably nearer 
the latter. 
Abactinally, the disk is limited by an interrupted circle of 
large plates, consisting of the basal supramarginals (S, in figure 
on plate V), the dorsal interradials (i), and five plates (r), one 
at the base of each ray, interpreted as basal radials. The basal 
supramarginals tend to be pentagonal in outline and the dorsal 
interradials are more or less broadly triangular or rhomboidal 
triangular, with the blunted apex of the triangle directed toward 
the suture between the basal supramarginals. In the accompa- 
nying figure, these outlines are best indicated in the interbrach- 
ial areas between rays I and V. In the other interbrachial arcs, 
the dorsal interradials tend to have a shallow indentation on 
the proximal margin. In the arc between rays I and V, the 
proximal halves of the basal supramarginals are separated by 
a rhomboidal triagonal area (m) filled by a material distinctly 
darker than that of the abactinal plates, and, although occupy- 
ing the position of a madreporite, its interpretation as such is 
extremely doubtful, especially in view of the absence of distinct 
radial striations. Similar dark material appears to occur in 
the sutures between some of the other plates on the abactinal 
surface. The plates interpreted as basal radials (r) are broadly 
pentagonal, with the very obtuse apex directed toward the distal 
end of the rays. In the accompanying figure, its outline is best 
shown on ray V, its blunt apex being directed slightly down- 
ward and toward the right, the plate being slightly displaced. 
