434 BALANID/E. 



narrow, with a small rounded spur, moderately distinct. The tips of 

 the crests for the depressor muscle barely depend beneath the basal 

 margin. 



Mouth : labrum considerably bullate, with the crest hairy and fur- 

 nished with a few most minute teeth. Palpi small, with their tips not 

 nearly touching each other. Mandibles with four teeth, of which the 

 lower ones are laterally double : inferior pectinated portion small. The 

 maxillae are notched, but their outline differed on opposite sides of the 

 individual examined. Outer maxillae bilobed on their inner face. 



Cirri. — The first pair has the rami unequal in length by about three 

 segments, having six segments on one and nine on the other ramus. In 

 the second pair the anterior ramus is remarkably short and extremely 

 broad ; the five segments of which it is composed being thickly covered 

 with bristles, some of which are very coarsely and doubly pectinated : 

 the posterior ramus is nearly twice as long as the anterior ramus, and 

 has eleven segments ; of these, excepting the two basal segments which 

 are rather thickly covered with spines, the others resemble in the 

 arrangement of their spines the four posterior pairs of cirri, with the 

 exception that there is a single transverse row of rather long spines 

 along the upper and inner lateral edge of each segment. The segments 

 in all the four posterior pairs of cirri resemble each other in bearing 

 each four pairs of main spines (of which the two lower pairs are short), 

 with a tuft of small intermediate spines. 



The penis is remarkable from its very small size and shortness, not 

 being more than once and a half as long as the pedicel of the sixth 

 cirrus. 



2. Octomeris BRUNNEA. PL 20, fig. 3 a, 3 b. 



Shell reddish-brown, depressed, thin, finely furrowed lon- 

 gitudinally : tergum with the basal margin having a slight 

 angular bend. 



Ilab. — Philippine Archipelago ; rare ; Mus. Cuming. 



General Appearance and Structure. — Shell circular, much depressed; 

 coloured brown, with an orange-red tint; surface regularly and nar- 

 rowly furrowed in longitudinal lines, the intermediate rounded ridges 

 projecting at the basal margin in finger-like points. The eight com- 

 partments, when disarticulated, are of nearly equal sizes ; the carino- 

 lateral and rostro-lateral compartments being rather smaller than the 

 others. The radii are neatly toothed; but with the exception of these 

 teeth, which are equally developed on both sides of the sutures, and 

 which closely interlock in the lower part of the shell, but stand a little 

 apart in the upper part, the radii can hardly be said to be developed. 

 The alae do not form a rectangular shoulder, the lower margin being 

 regularly curved into the parietes; the upper margin is only slightly 



