335 
sor only faintly indicated. Near the occludent margin the ridges 
of growth are accentuated by small hairs of the cuticle. 
The basal rostro-carinal diameter is 7,5 mm, the height of the 
carina 5 mm. 
The labrum (Fig. 70) is prominent but not bullate, with a 
deep notch and two or three minute denticles on the crest at the 
sides of the notch. 
Fig. 70. Acasta madreporicola, off Jolo. a labrum, b mandible, c maxilla 
d fifth segment of ciirus III, e fifth segment of the antenor 
ramus of cirrus IV, f median segment of cirrus VI. 
[a—c X 44, d—f X 88]. 
The mandible has three main teeth and three indistinct warts 
at the lower angle; delicate long hairs constitute a furry belt along 
the blade just inside the cutting edge. 
In the maxilla a notch is faintly indicated below the two stout 
upper spines; below this notch the cutting edge is armed with a 
single row of six somewhat shorter spines, and near the lower 
angle follow two more prominent spines, which are even longer 
than the two upper spines. A tuft of short bristles is indicated at 
the lower angle. The sides of the blade carry long, delicate hairs 
near the cutting edge. 
In the c irri segments of cirrus III are armed with hooks. 
The two basal segments as well as the two distal ones of the 
rami in cirrus III are devoid of hooks; the other segments have 
an anterior median row of 7 or 8 hooks turning their points to- 
