CIRRIPEDS FROM THE JUAN FERNANDEZ ISLANDS 49I 



Measurements in millimetres: 

 Carino-rostral diameter Height 



9 7.5 



The internal 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: Labruni with a deep notch and two or respectively three 

 teeth. According to Darwin » apparently without teeth, or with very minute 

 ones». Palpus not studied. 



Mandible with three distinct teeth. Below these there are two, confluent 

 with the lower point. The second tooth is distinctly double. 



Maxilla I 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 II 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 : 



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 III— 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. I. 1917, No. 205. 



Distribution: West coast of South America from the Strait of Magellan 

 to Pascamayo, Peru; Juan Fernandez Islands, 



