BARNACLES FROM DEEP-SEA CABLES. 291 



Aurivillius, from the West Indies and S. sinense, Armadale, from 

 the seas of Burma and China. It is, in any case, an extremely dis- 

 tinct species, remarkable for its large size, almost naked peduncle 

 and curious anal appendages. The regularity of the valves of the 

 hermaphrodite is a noteworthy feature and the comparatively large 

 size and high development of the male another. 



I have examined only the type-specimen, but there is, I think, 

 another from the same locality in the Raffles Museum. 



Subgenus Scalpellum, Leach. 



1910. Scalpellum (s. &.), Annandale, Sec. Ind. Mus., V, p. 150. 

 1913. Scalpellum (s. s.), id., ibid., IX, p. 227. 



Scalpellum hamulus, Hoek. 



1907. Scalpellum hamulus, Hoek, Siboga-Exp., mon. XXXI a (Cirr. Ped.), 

 p. 86, pi. vii, figs. 14, 14a. 



I assign to this species two comparatively large specimens 

 from Johul Bank 90 miles south of Timor (70 fathoms). They 

 were attached to the cable in the midst of a massive Alcyonarian 

 of the genus Dendronephthya. The capitulum in one specimen is 

 36 mm. long by 22 mm. broad, the peduncle 37 mm. by 11 mm. 

 The valves are tinged with pink, especially at the apices. The only 

 difference from Hoek's figure that I can detect is that all the lower 

 latera are relatively a little larger, the carina distinctly longer 

 and the upper margin of the tergum less sinuate above. The two 

 last characters are probably correlated. 



The cirri of this species are extremely- slender and the hairs 

 on their anterior margin very delicate. The basal segment of the 

 anal appendages is expanded and flattened, but much less so than 

 in 8. sociabile; it bears a long flagellnm-like process with about 

 sixteen segments, the exact number, as in 8. sociabile, being pro- 

 bably variable. 



Scalpellum sociabile, Annandale. 



1905. Scalpellum sociabile, Annandale, Mem. As. Soc. Bengal, I, p. 77, pi. 

 yiii, fig. 1. 



1908. Scalpellum sociabile, id. III. Zool. 'Investigator', Entomostraca, pi. 

 iii, fig. 9. 



The typical form, which is well represented in Capt. AYorsley's 

 collection, is more variable (in particular as to the mouth-parts 

 and the number of segments in the anal appendages) than I realized 

 when drawing up the original description. Indeed, the mandibles 

 of the specimen then dissected seem to have been altogether abnor- 

 mal (op. tit., 1905, p. 78, fig. 2). A characteristic feature of the 

 appendage is, however, shown even in the abnormal specimen, name- 

 ly the great distance between the first and second tooth and the 

 strong sinuosity or irregular outline of the margin between these 

 two teeth (cf. pi. vi, fig. 6). The form of the anal appendages, 



R. A. Soc, No. 74, 1916. 



