58 BULLETIN 00, UNITED STATES NATIONAL MUSEUM. 



The carinal latus is irregularly pentagonal, widest above the middle, 

 exceeding in area the upper and the rostral latera. The upper lateral 

 and carinal facets are equal and straight, the lower lateral longer, 

 straight, and the subcarinal margin still longer, concave. The basal 

 margin is shortest. The uml)o projects angularly be3"ond the carina. 

 In dorsal aspect the two carinal latera are seen to meet below the carina 

 in a straight suture as far up as their umbones. 



The peduncle is very short, covered with large imbricating scales 

 in five rows of four scales each. 



Length of the capitulum 5, breadth 2.5 mm. Length of the 

 peduncle L8 mm. Length of the carina 3.2 mm. 



This minute form is notable for the length of the plates of the 

 lower whorl, especiall}^ of the carinal latera, and for the shortness of 

 the carina. It is closely related to S. l>re)uca7H7iatam Hoek, but in 

 that antipodal species the whole capitulum is more lengthened, the 

 greatest breadth being decidedly less than half of the length. The 

 tergum is longer, the rostral lateral narrower and wedge-shaped, and 

 the subcarinal margin of the carinal latus is slightl}^ convex. The 

 roof of the carina in S. hrevicarinatum is described as "not quite 

 flat;" but in the present species it is strongly convex. S. niicrum 

 is known by a ■ single individual, which occurred with ScalpelluTn 

 longicarmaturit. (Fig. 21.) 



SCALPELLUM FORMOSUM, new species. 



Type.-C^i. No. 8975, U.S.N.M. 



Type-locality. — Albatross Station 2097, east from the mouth of Ches- 

 apeake Bay, north latitude 37° 56' 20", west longitude 70° 57' 30", in 

 1,917 fathoms, Globigerina ooze. 



Other localities. — Albatross Station 2205, south of Marthas Vineyard, 

 in latitude 39° 35' north, U.S.N.M. Cat. No. 32897. 



The capitulum is composed of 13 (or 1-i?) wholly calcified plates. 

 Ventral margin convex. The plates are sculptured with low, widel}^ 

 spaced, narrow wrinkles or ridges in the direction of lines of growth, 

 and fine, distinct, and close ril)lets radiating from the umbones. The 

 cuticle is very thin and sparsely clothed with rather long delicate hairs. 

 Sutures are linear. 



The scutum is trapezoidal, more than half as wide as long. Occlu- 

 dent margin convex; tergal, lateral, and basal margins are straight, 

 the basal shortest. There is a curved diagonal riblet from apex to 

 baso-lateral angle, stronger than the other radii. The acute umbo lies 

 slightly within the ventral margin. 



The tergum is triangular, with almost perfectly straight sides. It 

 is al)out li times the length of the scutum and more than twice as long 

 as wide. 



