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THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTOBY, 



[NINTH SERIES.] 



No. 24. DECEMBER 1919. 



XXXIX. — On Barnacles of the Genus Megalasma from 

 Deep-sea Telegraph- Gables. By W. T. Calman, D.Sc. 



(Published by permission of the Trustees of the British Museum.) 



The specimens here discussed form part of the collections 

 from telegraph-cables of which particulars were given in my 

 paper " On Barnacles of the Genus Scalpellum " *. Some 

 are from localities mentioned in the list of cable-ships given 

 in that paper, but there are also specimens from the vicinity 

 of Zanzibar (C./S. * Slierard Osborn '), the Java— Australia 

 and the Victoria-Tasmania cables (C./S. ' Recorder '), the 

 Tasman Sea (C./S. ' Patrol '), and the coast of Cuba (probably 

 from a cable). 



The species are all referred to the genus Megalasma of 

 Hoekf, as re-defined by Pilsbry J. It is distinguished from 

 Poscilasma by "the shape of the carina, which is enlarged at 

 the sides toward the base, with a concave plate inside.'" This 

 inner plate, however, does not always terminate above in 

 " two stout teeth," and the peduncle is sometimes far from 

 "very short" as in Pilsbry's definition. 



All except one of the species may further be included in 



* Ann. & Mag. Nat. Hist. (9) i. p. 96 (1918). 

 t Rep. ' Challenger ' Cirripedia, 1888, p. 50. 

 % Bull. U.S. Nat. Mus. lx. 1907, p. 87. 



Ann. & Mag. N. Hist. Ser. 9. Vol. iv. 27 



