THE BARNACLES IN THE U. S. NATIONAL MUSEUM. 73 



Compared with S. phantasma, of California, it is seen that S. 

 dicheloplax at no stage of growth has the base of the scutnni bifurcate, 

 the umbo of the carinal latus is recurved, and all the plates of the 

 lower whorl differ somewhat in shape, the upper calcified rami of the 

 rostral and carinal latera ascending less than in S. phantasma. 



SCALPELLUM DICHELOPLAX BENTHOPHILA, new subspecies. 



Typ<?.-C^t. No. 32878, U.S.N.M. 



Type-hmiUty. — Allmtross Station 2042, north latitude 39^ 33', west 

 longitude ^^"^ 27', between Cape May and Nantucket, 1,555 fathoms. 



The capitulum is more lengthened than in 8. dicheloplax., its length 

 twice the breadth. The carina is less arcuate with wider sides, and 

 separated from the tergum by a much narrower chitinous suture. The 

 plates of the lower whorl are completely calcified, and the inf ramedian 

 lateral plate is narrower, with central umbo. The scuta, terga, and 

 upper lateral plates are V-shaped, with comparatively shorter, wider 

 branches than in S. dicheloplax. (Fig. 28r7.) 



Length of capitulum 15, width 7.5; length of peduncle, 4.5 mm. 



The much more extensive calcification of the plates in the single 

 example of this subspecies, as compared with 8. dicheloplax^ may be due 

 to youth; but the narrower shape of the whole capitulum, the nar- 

 rower inframedian latera, and the reduction of the chitinous space 

 between carina and tergum are features which render it advisable to 

 distinguish this form by name. It requires comparison with speci- 

 mens of 8. dicheloplax of equally small size, which are unfortunately 

 not yet in our possession. 



SCALPELLUM PHANTASMA Pilsbry. 



1907. >S'. phantasma Pilsbry, Bulletin of the Bureau of Fisheries, XXVI, p. 194, 

 pi. VI, fig. 1. 



Type-locality.— Oil Santa Catalina Islands, California, 2,196 fathoms. 

 GROUP OF SCALPELLUM NIPPONENSE. 

 SCALPELLUM NIPPONENSE, new species. 



Type.— CM. No. 32909, U.S.N.M. 



Type-locality.— Albatross Station 3697, off Manazuru-zaki, Japan, 

 between 120 and 265 fathoms. 



The capitulum is elliptical, the length more than double the breadth, 

 with both ventral and dorsal margins convex; covered with a very thin, 

 smooth cuticle. It is composed of 13 imperfectly calcified plates, which 

 are lightly marked with growth lines. 



The scutum is subtriangular, the length nearly 2i times the greatest 

 breadth. The occludent margin is somewhat convex. The summit is 

 acuminate, a little recurved, and overlies the base of the tergum. 



