230 
Third pair (Pl. XXIV, fig. 2), branches somewhat unequal, of 10 and 11 segments. 
Hairs do not form such dense tufts as on 2™4 cirrus. Small but strong teeth along the anterior 
face of all the segments of the longer ramus. The teeth are arranged in groups of 2 to 4 on 
the distal half of the segments near the anterior margin, and in several rows. One of the 
spines situated on the tip of the last segment of this ramus is much stronger and looks 
almost like a claw. 
Fourth pair has 19 and 20 segments respectively in the two branches. The 5 or 6 lower 
segments of the slightly shorter branch (with 17 to 19 segments) bear small teeth, either single, 
or double, or in groups of 3 or 4 near the anterior face (Pl. XXIV, fig. 3). These teeth are 
not situated exactly on the margin of the segments, but at a short distance from it, on the 
surface of the segments. 
Fifth pair has 18 and 19, sixth 19 and 20 segments. Middle segments about twice 
as long as broad. Greatest number of pairs of spines on inner face 4 pairs. One of the hairs 
of the small group seen on exterior face of the segments, near the extremity, very long. 
Penis: long, tapering towards extremity, hardly any hairs on surface. 
The specimen of this species belonging to the collection of the Siboga, was found 
attached to a very long thread-like organism (a Gorgonacean) with distinct swellings at regular 
intervals. This seems to be Sczvfearella gracilis. The substance covering the, stem of the Gorgo- 
nacean is continued — as I pointed out above — over the surface of the Balanus; only after 
taking it away, I found that the said stem was quite enclosed in a longitudinal furrow of the 
slightly cup-formed basis. 
The animal was dredged at: 
Stat. 204, September 20, 1899. Lat. 4°20'S., Long. 122°58’E. The Station lies between the 
islands of Wowoni and Buton, northern entrance of Buton-strait. Depth 75—94 m. 
Bottom: sand, with dead shells. 
8. Sectio: Bathy-Balanus 
26. Balanus pentacrint n.sp. Pl. XXIV, fig. 4—10. 
Shell white, surface of valves more or less distinctly furrowed longitudinally. Orifice 
large, toothed. Radii broad, summits oblique, alae with rounded summits. Scutum distinctly 
furrowed horizontally, articular ridge prominent, no adductor ridge. Tergum with the surface 
somewhat undulating and the spur situated near the basi-scutal angle. Parietes, radii and basis 
without pores. Labrum without notch. 
This interesting deep-sea species connects the true Balani with the forms without radii, for 
which I propose to create the new genus Hexe/asma. In the present species the outer surface of the 
shell is white and smooth; in the older (larger) specimens it is distinctly furrowed longitudinally 
(especially so towards the basal margin), in the smaller ones, however, either not or only 
indistinctly so. It is, moreover, feebly striated horizontally. The radii are rather broad and have 
the summits oblique, they are distinctly striated horizontally; the alae are also broad and have 
the summits rounded. The orifice is toothed. The whole shell (Pl. XXIV, fig. 4), especially 
to2 
