EXPEDITION ANTARCTIQUE BELGE 



DESCRIPTION OF THE SPECIES 



i. — Balanus laevis Bruguière 



There are two sets of very small spécimens of a Balanus, which being quite young I think 

 it would be very difficult to détermine with certainty but for the very characteristic shape of 

 their scutum. The deep longitudinal furrow of that valve is very distinctly developed and 

 extends down towards the actual basai margin. They hâve conical shells with the surface 

 naked and white, with a small orifice and very narrow radii. There is only one slightly larger 

 spécimen, the greatest diameter of its basis measuring 3 mm., and in this spécimen the 

 whiteness of the surface is not so apparent ; ail the other spécimens — ail together about a 

 dozen — are much smaller, their basis measuring from not quite i to about 1.5 mm. and 

 thèse hâve ail perfectly naked and white shells. 



This species has been collected at différent places along the coast of South-America : 

 Peru, Chili, Tierra del Fuego. According to Darwin it occurs moreover in California and 

 Weltner (') makes mention of spécimens from Brasil. Darwin distinguished, besides the 

 typical form, two varieties ; but the little animais collected by the Belgica seem to belong to 

 the typical form as described by Darwin. 



Both lots were collected Lapataïa, Beagle Canal, Tierra del Fuego, Argentine, December 

 24 th , 1897. The one was found on the rocks amidst calcareous Algae and Serpulidae, at the level 

 of high water. The other lot was taken from the carapace of Halicarcinus planatus. 



2. — Elminius Kingi J. E. Gray 



This species was met with on two différent occasions : once at Hope Harbour (Clarence 

 Island) and once at Lapataïa (Beagle Canal). It is a very characteristic form and is represented 

 by numerous spécimens from both localities. 



Darwin knew this species from Tierra del Fuego, the Falklands Islands and Chiloë ; 

 Weltner (1. c.) names also Puerto Mont (Chili) as one of the localities from which the Berlin 

 Muséum has spécimens ; Gruvel ( 2 ) adds Puntas-Arenas and Orange Bay to the list. They are 

 ail places situated in sub-antarctic South-America and the distribution of this species seems 

 to be limited, therefore, to the southern part of this continent. 



With regard to its occurrence at the two stations where it was collected during the cruise 

 of the S. Y. Belgica, the following annotations were made : 



Hope Harbour, Clarence Island, Magdalen Sound, Magallanes, Chili. December I4 th , 

 1897. Covers the rocks complet ely, hère and there, at high water level. 



Lapataïa, Beagle Canal, Tierra del Fuego, Argentine. December 24 th , 1897. Very 

 common on the rocks, the Patellas, and especially the Mytili which form continuous layers 

 round the Bay, at half-tides level. Also very common on the rocks, at highwater level. 



(1) Wei.tner, W., Verzeichnis der beschriebenen Cirripedienarten. Archiv f. Naturgeschichte, 1897, I, S. 2Ô3. 



(2) Gruvel, A., Monographie des Cirrhipèdes. Paris, 1905, p. 294. 



