118 



BULLETIN 111, UNITED STATES NATIONAL MUSEUM. 



CADULUS (PLATYSCHIDES) RUSHII ARNE, new subspecies. 



Plate 18, fig. 9. 



This is a smaller form than Gadulus rushii rushii and hardly to be 

 distinguished from it except in the matter of size, but the difference 

 is sufficiently persistent to warrant a separation. Geographically it 

 occupies the same range. The apical features of the shell are re- 

 maikably well shown in some specimens. These consist of four 

 shallow slits and four lobes, the dorsal and ventral lobes low and 

 broad, the lateral ones narrow, triangular, and pointed. 



The type, Cat. No. 314729, U.S.N. M., measures— length, 8.3 mm.; 

 diameter, 1.3 mm.; anterior aperture, 1.2 mm.; apical aperture, 0.8 

 mm. It was dredged at the U. S. B. F. Station 2234, off New Jersey, 

 in 810 fathoms, bottom of green mud, temperature 38.6°. 



The followinp; are the National Museum lots: 



1 Type. 

 CADULUS (PLATYSCHIDES) PANDIONIS Verrill and Smith. 



Plate 18, fig. 10. 



1880. Cadulus pandionis (Verrill and Smith) Verrill, Amer. Journ. Sci., vol. 20, 



pp. 392, 399. 

 1880. Cadulus pandionis Verrill and Smith, Proc. U. S. Nat. Mus., vol. 3, p. 395. 

 1882. Cadulus pandionis Verrill, Trans. Conn. Acad. Arts and Sci., vol. 5, p. 558, 



pi. 58, figs. 30, 30 (a). 

 1885. Cadulus pandionis Verrill, Rep. of Com. Fish and Fisheries for 1883, 



Article 16, p. 573. Also Bush. Rep. of above, Art. 17, p. 717. 

 1898. Cadulus {Gadila) pandionis, Pilsbry and Sharp, Tryon's Man. Conch., 



vol. 17, p. 171, pi. 25, fig. 63. 

 1915. Cadulus pandionis, Johnson, Occ. Papers of Boston Soc. Nat. Hist., vol. 7, 



No. 13, Moll., p. 84. 



The shell is large (10 to 11 mm.), strongly curved, gradually accele- 

 rating in diameter from a small apical orifice to the equator, at which 

 point there is a considerable swelling, especially on the convex side; 

 the section of maximum size is about one-third distance from the 



