52. Cirripeds from the Juan Fernandez Islands. 



By 

 C. A. NILSSON-CANTELL. 



With 3 text-figures. 



A number of cirripeds, collected by Dr. KAre Backstkom, were brought 

 home by the expedition of Prof. C. Skottsberg to the Juan Fernandez 

 Islands in 1916 — 1917. They are preserved in the Zoological Museum at 

 Gothenburg. 



From the west coast of South America many cirripeds have been reported, 

 but their exact distribution is not well known. Barnacles from Juan Fernandez 

 were collected by Dr. PLATE and described by Dr. Weltner (1895). He 

 found 13 species along the coasts of Chile belonging to the genera Concho- 

 derma, Lepas, Coronula, Balanus, Chthamalus and Verruca. Only two were 

 taken at Juan Fernandez viz. Lepas anatifera and Chthamalus cirratus, but 

 many of the others mentioned probably occur, as two of them, L. australis 

 and Balanus psittacus, are represented in Dr. Backstrom's material. 



The following species have been identified by me: Lepas pectinata, anati- 

 fera, australis and Balanus psittacus. As the three first mentioned are pel- 

 agic with a wide distribution and the last is well known, not much need here 

 be added as regards the distribution. Yet the material is of some interest as 

 it confirms what has been pointed out by several authors (see also NlLSSON- 

 Cantell, 1927, p. 752 and 1928, p. 13) that Lepas species are very variable 

 and that it sometimes is difficult to fix an exact limit between the different 

 species. All that we can do now is to give figures of the described specimens 

 belonging to the more variable Lepas species. If this had been done before, 

 many mistakes might have been avoided. In the collections of the museums 

 I have found many wrong determinations, certainly made because this genus 

 is considered to be very easy to deal with. 



By comparison with the material of L. australis taken by Dr. Plate 

 and described by Weltner I have been able to prove that L. australis is 

 represented in this part of the world by a form differing from the typical 

 species. I regard this form as a new variety. 



I wish to express my thanks to Dr. N. Odhner, Stockholm, and Prof. 

 Dr. A. Schellenberg, Berlin, who have given me the opportunity to make 

 a comparative study of the Lepas specimens preserved in the museums under 

 their charge. 



