126 



BULLETIN 111, UNITED STATES NATIONAL MUSEUM. 



Length, 6.5 mm.; diameter, 1.25 mm. (Dall). 



Length, 7 mm.; diameter, 1.10 by 1.30 mm.; anterior aperture, 

 0.75 mm. ; apical aperture, 0.4 mm. (Barbados). 



The type, Cat. No. 95376, U.S.N.M., is from Barbados, taken in 

 100 fathoms. 



The distinguishing feature of this little shell is the decided dorso- 

 ventral compression which separates it at once from its nearest rela- 

 tives — Cadulus lunula and C. simpsoni. 



The following additional lots in the National Museum collection 

 are all from the dredgings of the State University of Iowa Expedition 

 to Barbados in 1918. 



Locality. 



Remarks. 



Barbados, S. U. I. Exp. Station SS 

 Barbados, S. U. I. Exp. Station 3.. 

 Barbados, S. U. I. Exp. Station 51 

 Barbados, S. U. I. Exp. Station 40 

 Barbados, S. U. I. Exp. Station 69 

 Barbados, S. U. I. Exp. Station 48 

 Barbados, S. U. I. Exp. Station — . 

 Barbados (Blake collection) 



— fms. 

 75-SO fms. 

 35 fms. 



90 fms. 

 60-70 fms. 

 80 fms. 



— fms. 

 100 fms. 



CADULUS (PLATYSCHIDES) LUNULA Dall. 



Plate 19, fig. 12. 



1881. Cadulus lunulus Dall, Bull. Mus. Comp. Zool., vol. 9, p. 35. 



1889r- Cadulus lunula Dall, Bull. Mus. Comp. Zool., vol. 18, p. 431, pi. 27, fig. 8, 



in part. 

 1889. Cadulus lunula Dall, Bull. 37, U. S. Nat. Mus., p. 78, pi. 27, fig. 8, in part. 

 1898. Cadulus (Gadila) lunula, Pilsbry and Sharp, Tryon's Man. Conch., vol. 



17, p. 167, pi. 25, fig. 55, omitting Cape Lookout reference. 

 1903. Cadulus lunula Dall, Bull. 37, U. S. Nat. Mus., p. 78, pi. 27, fig. 8, in part. 



Doctor Dall's type is a broken specimen, leaving both the diagnosis 

 And the figure necessarily incomplete. I have hesitated to refer any 

 National Museum specimens to the species, as the type fragment may 

 be liberally interpreted to fit several of the smaller Antillean Caduli. 

 However, a single specimen from Barbados in the museum collection 

 seems to be referable with certainty to the species, despite the differ- 

 ence in depth station. The steepness of the continental shelf off 

 northwest Cuba and the swiftness of the oceanic current that sweeps 

 by it may account for the finding of a dead fragment at depths in 

 excess of that of the natural habitat of the species. The supplemental 

 description here given follows as closely as possible the original one, 

 the additions being bracketed. 



The shell is translucent [semitransparent], white, smooth, destitute 

 of sculpture; dorsum (that is the concave outline) is nearly straight 

 [except for a gentle arch in the posterior portion], slightly inflated 

 [at the equator, which is located at about the anterior third; the 



