228 



Cirri. Cirrus of second pair has slightly unequal branches of 6 and 7 segments. 

 Segments are not protuberanl, but their surfaces are distinctly rounded near distal extremity. 

 Dense tufts of hairs are disposed on these rounded surfaces. 



Cirrus of third pair (PI. XXIII, fig. 15) is slightly longer than that of 2 nd pair, and has 

 8 and 9 segments in the two branches. The antenor margin of each segment is distinctly 

 rounded near the middle, and furnished with a group of hairs which does not form a tuft 

 and is considerably less dense than that on the corresponding segments of the 2 n,J cirrus. 

 With the exception of the last ones, the segments of both rami show a longitudinal row of 

 small teeth between the hairs. These are slightly more distinct on the segments of the longer 

 ramus and somewhat smaller on the first or basal segment of each ramus. A few smaller 

 teeth are disposed on the surface of most segments, forming indistinct rows, parallel to the 

 main row along the margin. 



Cirrus of fourth to sixth pairs have the number of segments varying from 15 to 17. 

 Greatest number of pairs of spines (PI. XXIII, fig. 16) seen on anterior face of segments 

 is 4. Of the group of hairs on exterior face near the extremity of the segments, one hall- 

 as a rule is much longer and stronger than the others. 



Penis very long, few hairs on the surface, and hardly any at the extremity; rather 

 thick and stout at the basis, tapering towards the extremity, which is narrow, almost pointed. 



The specimen was collected at : 



Stat. 164. August 20, 1899. Lat. i°42'.5 S., Long. i30°47'.5E. Depth 32 m. Bottom: sand, 

 small stones and shells. It was found attached to a small piece of a brown stem, 

 which, perhaps, is that of a species of Gorgonia. 



General Remarks. In outward shape this species comes nearest to B. galeatus 

 Linn., from which it is distinct, however, by the horn-like transverse excrescences of the laterals 

 ancl by the absence of the carino-laterals. I think this is the first instance of a species of 

 Balanus really showing only f o u r compartments 



25. Balaiius proripicns n. sp. PI. XXIII, fig. 17 — 21. PI. XXIV, fig. 1 — 3. 



Carino-lateral narrow, rostrum elongate. Basis with a longitudinal furrow. Scutum with 

 the articular ridge well-developed and reflexed. Tergum broad with a very wide spur. 



This new species is proposed for a form from rather deep-water (75 — 94 m.) that no doubt 

 shows some resemblance to several species of Darwin's section B, but which, however, I think 

 best to describe as a new species. It is represented by a single specimen: so as not to injure 

 the specimen I refrained from investigating the structure of its parietes and basis. lts nearest 

 relation, to judge by the shape of the opercular valves (the only parts of that species figured 

 in Darwin's Monograph), seems to be B. cymbiformis Darwin. 



The shape (PI. XXIII, fig. 17) is elongate, lateral and rostrum, appear to creep 

 along the thread-like stem of the Gorgonia. The shell is flattened laterally, the colour of the 

 parietes and basis is white, with the exception of the carina, carino-lateral and adjacent parts 

 of the lateral, which are pale-reddish, with slightly darker reddish longitudinal stripes. The 



