THE BARNACLES IN THE U. S. NATIONAL MUSEUM. 9 



latus," since it is clearly, by form and position, a member of the lower 

 whorl of plates. It is, however, clearly homologous with the plate 

 which became an upper latus in the more advanced and specialized 

 fornls of Scalpe/luDi. An intermediate stage is represented by S. pol- 

 llcipedoldes Hoek " and various other species. 



The two species to be described below belong to two rather distinct 

 groups of this subgenus, definable as follows: 



I. Section CaJantica s. str. Plates of the lower whorl low and wide, 

 triangular, small and separated, not concealing the bases of the upper 

 whorl of plates. Scales of the peduncle minute. Plates covered with 

 a distinct cuticle. Western Pacific. 



S. vUlosum Leach, "Eastern Seas." 

 S. poUielpedoides Hoek, south of New Guinea. 

 S. trisjnnosum Hoek, Sulu Sea, 82-102 fathoms. 

 8. eos Pilsbr}', Japan, 71 fathoms. 



II. Section SciUielepas Seguenza. Plates of the lower whorl well 

 developed, high and recurved, covering the bases of those of the upper 

 whorl. Peduncle very short, covered with scales of moderate size. 

 Plates conspicuously calcareous, not covered with a distinct cuticle. 

 Atlantic and Arctic oceans.* 



S. calyculus Aurivillius, Azores, 850-900 meters. 



S. falcatum Aurivillius, Azores, 4.51: meters. 



S. gemma Aurivillius, Greenland, 1,800 meters. 



S. swperbum Pilsbry, off S. E. United States, 352-440 fathoms. 



S. gri/maldi Aurivillius, Azores, 845-1,230 meters. 



SCALPELLUM EOS, new species. 



Type.—C'Ai. No. 3287T, U.S.N.M. 



Type-locality, — Alhatross Station 3741, off Ose-zaki, Hondo, Japan, 

 in 71 fathoms, on a large Balanus. 



The capitulum is subtriangular, compressed, the ventral margin 

 nearly straight, with armour of 13 plates, those of the lower whorl 

 very small and inconspicuous; covered with a smooth, yellowish cuti- 

 cle. The plates are lightly marked with lines of growth and a few 

 weak coarse radial strije on the ventral half of the scutum. Sutures 

 linear. The umbones of all the plates are apical. 



«See Hoek, Koninklijke Akademie van Wetenschappen te Amsterdam, Proceed- 

 ings of the section of Sciences, VII, p. 92, figs. 4-6 (Dec, 1904). 



''The group Scillxlepas was established by Seguenza in 1872 for Italian and Sicilian 

 miocene and pliocene forms, with the tyi)e S. carinatus {PoUicipescai'lnatus'PhUip-pi). 

 It was correctlj' recognized as a group intermediate between PolUcipes and ScalpeUum. 

 The earlier species appeared in the Cretaceous. The miocene and pliocene forms 

 are very closely related to modern deep-water species of the Atlantic, and should be 

 carefully compared therewith. Good descriptions and figures of them may be found 

 in (t. de Alessandri, Studi Monografici sui Cirripedi fossili d' Italia, in Palaeonto- 

 grajjhica Italica, XII, 190G, pp. 243, 263. 



