RETUSA. 215- 



lightly inflexed in the middle ; columella short, receding, hardly- 

 folded. Surface very smooth and a little shining, without spiral 

 lines, the growth strife rather inconspicuous. Alt. 3*5 mill. (Sars.)' 

 Sccmdaiiavia ; Northern shores of Great Britain. 



Cylichna nitidula Loven, Ind. Moll. Skand. p. 10. — Forbes & 

 Hafley, Hist. Brit. Moll, iii, p. 515, pi. 114e, f. 6. — Jeffreys^ 

 Brit. Conch, iv, p. 412. — Utri cuius nitidulus Sars, Moll. Reg. Arct. 

 Norv. p. 286, pi. 17, f. 13 (shell) ; pi. 26, f. 3 (animal). 



This species has somewhat the aspect of the forms referred to Cy- 

 lichnwa, but not their sculpture. Compare C. umbilicata Mont. 

 Sais has shown nitidula to be a Retusa by an examination of the 

 soft parts. 



R. ROBAGLiANA Fischer. PI, 27, fig. 6. 



Shell elongated, cylindrical, whitish, rather solid, not umbilicated, 

 a little dilated below, slightly narrower above ; longitudinally 

 densely costellate, the costae close, regular, not sinuous, and some- 

 what latticed with spiral stripe, decussating the riblets. Spire um- 

 bilicate, excavated. Aperture elongated, with subparallel margins ; 

 columellar margin short, reflexed. Alt. 3, diam. \h mill. (Folin.} 



Gulf of Gascony, 



Bulla rohagliana Fischer, in Les Fonds de la Mer, i, p. 150, pi. 

 23, f. 2 ; Acte? Soc. Linn. Bord. xxix, p. 197. 



This species belongs to the group of nitidula and umbilicata, but 

 is distinguished by the peculiar scul2:)ture of the shell. 



R. LACTEA Jeffreys. Unfigured. 



A small fragment of another species occurred at Station 12, 1450^ 

 fathoms. It consists of the anterior portion of a short cylindrical 

 shell which is of a milk-white color, glossy, and marked with slight, 

 rather distant, spiral strife or rather impressed lines ; the sculpture 

 does not extend to the crown ; the apex is semiglobose, and sunk 

 within a sharp obliquely encircling ridge. The species may be 

 called lacteus. I also dredged a young specimen of this species irti 

 the ' Porcupine' Expedition of 1869, off the west coast of Ireland,, 

 at a depth of 1443 fathoms (Jeffr.). 



North Atlantic 



Utriculus lacteus Jeffr., Ann. Mag. Nat. Hist. (4), xix, p. 334. 

 15 



