2 20 



Fourth pair has the rami unequal, having 11 and 15 segments respectively. The lower 

 segments are shorter, the upper segments are more elongate, 2 1 /., to 3 times as long as broad 

 This is the case in most species of Balanus\ it is somewhat exceptional, however, that while 

 the 3 distal segments of the shorter and the 5 distal segments of the longer ramus are furnished 

 with only three pairs of spines of different size on their inner faces, the lower segments have, 

 in addition, a row of downwardly-curved teeth developed along the anterior margin, rovvs of still 

 smaller teeth being disposed on the inner face, in the same way as they are observed on the 

 cirri of the third pair of this species. Of the shorter ramus, the first segment shows only one, 

 and the second segment a few of these teeth, they are well-developed on segments 3 to 7, 

 still represented by a few on segment 8, and not seen at all on segments 9 to 11. The 

 longer ramus shows a few of them on segments 1 to 3 and 9 to 10, the segments 4 to 8 

 have them fully developed, and the segments 11 to 15 have none at all. Of the 3 pairs of 

 spines observed on the upper segments, only two are seen on most of the lower segments. The 

 tufts of spines on the dorsal surface of the segments, close to its upper margin, are only 

 feebly developed. 



Fifth pair has nearly equal rami of 16 and 17 segments. The lower segments are 

 shorter, the upper segments elongate. The number of pairs of spines on the inner face of 

 each segment is 3, a fourth pair of extremely short ones being already seen on several 

 segments. The segments 5 to 9 are furnished in both rami of this cirrus with the same rows of 

 teeth (PI. XXII, fig. 17) which are seen on the middle segments of cirri 3 and 4. The teeth 

 alonaf the anterior marmn of the segments of this cirrus are not so strong, however, as the 

 corresponding ones of the preceding cirrus. The lower segments are furnished, on the dorsal 

 surface, close to their upper margin, with a small tuft of spine-like hairs, one of which is nearly 

 as long as the segment itself. 



Sixth pair has nearly equal rami of 20 and 21 segments. Middle segments elongate, 

 2 l J„ to 3 times as long as broad, slightly broader towards distal extremity. Most segments are 

 furnished on their inner face with four pairs of spines ; the last pair of these is of greater length 

 than the segment itself, the penultimate is a trirle shorter than the segment, the other two 

 pairs being short and extremely short respectively. The rows of teeth which are observable on 

 the inner faces of the middle segments of the 3" 1 to 5 th cirri are completely wanting on the sixth 

 cirrus (PI. XXII, fig. 18). The tufts of spinedike hairs on the dorsal surface of each segment 

 are only feebly developed. 



On the pedicels of the 4 ,h to 6 th cirri on both segments, near the anterior face and the 

 upper extremity, a group of small spinedike teeth of the same shape as those on the segments 

 of the 4 th and 5 lh cirri, but smaller, can be made out. 



Penis of moderate length, tapering towards the extremity and with a few hairs scattered 

 over the surface. 



This species was collected during the cruise of H. M. S. "Siboga" at: 



(± Stat. 231). November 14 — 18, 1899. Ambon-anchorage, Reef-exploration. The depth at the 

 anchorage was 40 m., but it was not noted at the place wh'ere the small Balani 

 were collected. Bottom : coral-sand. 



