XIV. THE INDIAN BARNACLES OF THE 

 SUBGENUS SC ALPELLUM. 



By N. Annandale, DSc, F.A.S.B., Superintendent of the Indian 



Musetim. 



In a former paper ^ I have discussed the subdivision of the 

 genus Scalpellum and reviewed the indigenous species assigned to 

 the subgenus Smilium. At present I propose to consider the 

 remaining Indian species of the genus, that is to say those which fall 

 into Hoek's^ divisions Arcoscalpelluni and Mesoscalpellum or into 

 the subgenera recognized b}^ Pilsbry ^ under the names Arcoscalpel- 

 luni and Scalpellum. It seems to me unnecessary to assign to these 

 species more than subgeneric rank and I therefore include all 

 under the common designation Scalpellum {s.s.) or subgenus Scal- 

 pellum. 



To this subgenus I2 Indian species are here attributed, one of 

 them not having as yet been described. This and three others are 

 only known from the seas of British India ; four are known from 

 the Malay Archipelago (one of them also from the western part of 

 the Indian Ocean) and one from the Mid-Pacific ; one is found in 

 the deeper parts of the western Pacific and the southern Atlantic 

 as well as those of the Indian Ocean ; one is identical with a 

 species described from the northern Atlantic off the American 

 coast , and one has an extended distribution in both the Atlantic 

 and the Indian Oceans. All are deep-sea forms only found, at 

 any rate in tropical waters, at depths greater than one hundred 

 fathoms. It is possible that the Scalpellum-isiunsi of the seas of 

 British India will ultimately be proved capable of division into 

 three geographical groups, of which one has a very restricted range, 

 one is distributed in the deeper parts of the Indian and the western 

 Pacific Oceans, while the third is scattered in the Indian and 

 Atlantic Oceans at great or considerable depths. Most of the species 

 are, however, as yet known from but few specimens and it is there- 

 fore not surprising that the distribution often seems to be extra- 

 ordinarily discontinuous. This fact also makes it impossible to be 

 dogmatic as regards specific limits, for variation is great in some 

 species that are well known. 



The following list gives the names of the species as yet recorded 

 from the Bay of Bengal and the Arabian Sea, and also a general 

 statement as to the known range of each : — 



1 Rec. Ind. Mus. V, p. 145, 1910. 



4 Siboga-Exped., Mon. XXXIrt, p. 58, 1907. 



3 Proc. Acad. Nat. Sci. Philadelphia, p. 104, 1908. 



