240 
face of each segment, and those situated at and near the upper extremity of the outer 
surface of the segments not so dense as those on second cirrus. 
The fourth cirrus (Pl. XXV, fig. 3) has 24 segments in the shorter (anterior) ramus 
and perhaps a few more in the other — this ramus being broken off in both cirri. Last 
segment of pedicel with a row of teeth along the front margin, which looks perfectly like a saw 
in consequence. The teeth increase only very slightly in size from the base of the segment 
towards the tip. A large number of segments of the anterior ramus show a series of such 
teeth along the inner margin, the number of these teeth varying from 4 to 6 on the 12 lower 
segments of this ramus. The teeth are somewhat claw-like and directed downwards, growing 
somewhat smaller from the lower towards the upper segments. The 12th segment has only 4 
of these teeth; the segments 13 to 15 have also 4, but they are directed upwards with their 
tips. The segments 16 to 19 have 3, 2, 2 and 1 respectively of these teeth, which, moreover, 
grow gradually smaller. The posterior ramus has no teeth on the ro lower segments, and has 
rows of 4 to 6 teeth along the inner face of the 9 following segments. These teeth are generally 
somewhat smaller than those on the anterior ramus and are, as a rule, directed upwards. The 
distal part of the inner face of each segment, in both rami, is furnished with a group of 
spines which represent the pairs of spines seen on the segments of the other cirri: the lower 
segments have only one pair, the following two to three pairs, placed so close together as to 
touch each other at the basis. 
The cirrus of the fifth pair has elongate rami of 26 to 28 segments. Several segments 
of the anterior ramus — in the specimen I investigated more carefully, segments 3 to 24 — 
have the inner face or front margin furnished with a row of teeth, of the same shape but a 
little smaller and less numerous than those along the segments of the 4 cirrus. As a rule 
each row has three such teeth, sometimes, however, four or even five. They are completely 
wanting on the posterior ramus. They are as a rule curved downwards. The segments of the 
posterior ramus are furnished on their inner face with three pairs of spines. They are inserted 
along the upper half of the inner margin, yet not crowded together. On the outer face of 
each segment, close to its upper margin, a small group of delicate spines is situated: these 
are longer on the lower than on the upper segments. . 
The cirrus of the sixth pair has nearly equal rami of about 30 segments. The segments 
grow — as in the other cirri — somewhat longer and more slender, from the basis to the 
tip of the cirrus; they become, even where they are most slender, not longer than three times 
their breadth. 
Penis long, rather thick at the basis, growing very narrow towards the extremity. 
Surface furnished with numerous short hairs which stand off perpendicularly from the surface. 
This interesting species is not represented in the collection of H. M. S. ‘Siboga’’. It 
was sent to me with other Cirripedia taken in the Western part of the Malay Archipelago. 
As it was studied by me along with other species of the same genus collected by the Siboga 
in those waters, I think its description can be usefully inserted at this place. The exact locality 
of its occurrence was: 
H. M.S. “Gier”, N° 12, Experiment 13. Lat: 6°15'S., Long. 110°50’ E. Depth 40—so m: 
II2 
