154 



tenuis were already known to inhabit the Malay Archipelago ; they have not been observed 

 outside that region so far I know. B. terebratus Darwin was not known to occur in the 

 Malay Archipelago : Darwin reported, that the habitat of this species was unknown to him. 

 In two recent papers (one l of Borradaile and one 3 of Annandale) this species is mentioned, 

 as probably occurring in the Maldive and Laccadive Archipelagoes and at Ceylon. This is, of 

 course, by no means improbable ; but as these specimens did not show the peculiar structure 

 of the basis, which struck Darwin and caused him to give the species its name and 

 which is indeed very striking, some doubt remains whether the above-named authors really 

 met with it. 



There is, after all, to judge from our present knowledge, some reason to admit that 

 the Malay Archipelago has its special fauna of species of Balaiuis. Of course this cannot be 

 proved, since any species, which at present is known from that region only, may afterwards 

 be found to occur outside it. And even the great number of species that have been observed 

 in this region does not prove much in this respect. In this connection, I wish to point out also, 

 before leaving the subject, that several species of Balanus have been observed in regions 

 bordering on the Malay Archipelago, which seem to be absent in that region itself: namely 

 B. nigrescens Lamarck from West-Australia, B. cymbiformis Darwin from Madras, B. carenatus 

 Gruvel from Akyab (Burma), B. allium Darwin from Ceylon and Australia, B. vcstitus Darwin 

 and B. imperator Darwin from New South Wales, and B. acncas Lanchester from Manaar. 

 But here again the same must be kept in mind, namely that no matter how carefully a region 

 may be explored, several species may still be found there which hitherto have escaped observation. 

 In consequence of the difficulty of the determination, it is even possible that one or more of 

 the species described as new in this report, may after all turn out to be identical with one of 

 those described already. For example, my new B. arcuatus may be found to be the same as 

 Darwin's B. allium, as is explained by me in this report, where the description of my new 

 species is given. The latest publications I have seen in which species of Balanus also were 

 described, and which treat of the Cirripedes of East-Asia, are Paul Krüger's paper (1. c.) 

 which forms a part of Doflein's contributions to the natural history of East India, and Pilsbry's 

 paper on the Barnacles of Japan and Bering Sea. Both papers were published in the course 

 of 191 1. According to Krüger, Balanus is represented in East Asia by 13 species and in 

 Doflein's collections by 8, two of which only, viz. B. tintinnabulum and B . amphitrite, were 

 collected also during the expedition of H. M. S. "Siboga", in the Malay Archipelago — but, 

 as is well-known, and is said already (p. 153), these are both species with a world-vvide 

 distribution. Of the other six species of Krüger, one (B. corolliformis) may remain undiscussed 

 here, it being one of those which I propose to include in a new genus ; one [B. trigonus), which 

 is represented by numerous samples collected in Japan waters, is, according to Darwin, found 

 also in the Malay Archipelago, and in Australia ; three (B. crenatus, B. rostratus and B. cariosus) 

 which were collected also in Japan, are species known hitherto from only temperate and colder 



1 BoRRADAII.E, 1. c. 



- ANNANDALE, N., On the Cinipedia (of the Gulf of Manaar). In Herdman's Report on the Pearl Oyster Fisheries, published 

 by the Royal Society, 1906. 



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