CIRRIPEDS FROM THE JUAN FERNANDEZ ISLANDS 491 
Measurements in millimetres: 
Carino-rostral diameter Height 
9 75 
The zternal parts are mentioned by DARWIN (1854) but no figures are 
given. Figures and a supplementary description of my specimen may be 
given here. 
. Mouth-parts: Labrum with a deep notch and two or respectively three 
teeth. According to DARWIN »apparently without teeth, or with very minute 
ones». /alpus not studied. 
Mandible with three distinct teeth. Below these there are two, confluent 
with the lower point. The second tooth is distinctly double. 
Maxilla [ has a distinct notch with smaller bristles under the two upper 
stronger spines. The lower part at the front edge projecting, with two stronger 
spines. The inferior angle with smaller spines. 
Maxilla LI bilobed. The outer lobe is strongly curved and separated 
from the inner lobe, which is convex. Both lobes with long bristles. The 
mouth-parts agree well with the short description by DARWIN (1854). 
Number of segments of the cirri: 
I II Il IV V VI 
Tere Iie iP) 13 14 22 — (14 18) 21/23 
Cirri I—III much shorter than the other. Cirrus I with unequal rami; the 
shorter has very protuberant segments. Cirrus II with rami equal in length, 
both with very protuberant segments. Cirrus HI—VI with rami equal in 
length. It is of interest to note that cirrus V at the one side was regenerated. 
In my study of the cirripeds I have previously found regenerated cirri, but not 
very often. Experiments I have made on living specimens have not given 
positive results. This regenerated cirrus was also shorter and deformed and 
had a smaller number of segments. The cirri thus do not seem to attain the 
normal size and number of segments after regeneration, 
Locality: Masatierra, Cumberland Bay. On a buoy, 3. 1. 1917, No. 205. 
Distribution: West coast of South America from the Strait of Magellan 
to Pascamayo, Peru; Juan Fernandez Islands. 
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