220 
Fourth pair has the rami unequal, having 11 and 15 segments respectively. The lower 
segments are shorter, the upper segments are more elongate, 21/, to 3 times as long as broad 
This is the case in most species of Lalanus; 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 anterigr margin, rows 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 g 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 g are furnished in both rami of this cirrus with the same rows of 
teeth (Pl. XXII, fig. 17) which are seen on the middle segments of cirri 3 and 4. The teeth 
along the anterior margin 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'/, 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 trifle 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" to 5t cirri are completely wanting on the sixth 
cirrus (Pl. XXII, fig. 18). The tufts of spine-like hairs on the dorsal surface of each segment 
are only feebly developed. 
On the pedicels of the 4'* to 6‘ cirri on both segments, near the anterior face and the 
upper extremity, a group of small spine-like teeth of the same shape as those on the segments 
of the 4t® and 5‘ 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 where the small Balani 
were collected. Bottom: coral-sand. 
92 
