334 
These compartments are externally feebly granulated and ribbed, 
the ribs radiating from the apex. The cari n o-l a te ra 1 compartment 
is obliterated, only leaving behind the broad radius and ala in the 
same way as in Acasta Dofleini. There are no perforations nor 
pores in the compartments or in the bowlshaped basis. The shell 
is quite white, and of a strong and rather solid structure, devoid 
of pores between the basal parts of the compartments. The attach* 
ment of the compartments to the basis is very strong. — The 
radii are delicately transversely striped; the upper margin is 
Fig. 69. Acasta madreporicola, off Jolo. a entire aniraal (side view), the coral 
prepared off above the basis of the cirriped ; b and c external view of 
tergum and scutum, d and e inside view of scutum and tergum. 
[a x 4, b—e X 6]. 
crenulated, and oblique in the same way as that of the al ae. All 
radii reach to the basis. 
The scuta have strong ridges of growth ornated with very 
feeble transverse striae, which nevertheless do not lend the plate 
a radially striped appearance. The articular ridge is very promi¬ 
nent, and almost as long as the entire tergal margin; the articular 
furrow on the other hånd is shallow. There is a deep pit for the 
lateral depressor. An adductor ridge is only just indicated, whereas 
the pit for the adductor is very deep although narrow. 
The terga are extremely brittle. The spur is about half as 
wide as the basal margin, or even a little wider; its margin is 
confluent with the basi-scutal point of the plate. The spur fasciole 
is almost invisible, and the ridges of growth very feeble. The art¬ 
icular area is very broad and shallow, and ridges for the depres- 
