RETUSA. 21 



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



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



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



Scandanavia ; 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. Utriculus 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- 

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

 Sars 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 urnbilicated, 

 a little dilated below, slightly narrower above ; longitudinally 

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

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

 bilicate, excavated. Aperture elongated, with subparallel margins ; 

 columellar margin short, reflexed. Alt. 3, diam. 1 mill. (Folin.y 



Gulf of Gascony. 



Bulla robagliana FISCHER, in Les Fonds de la Mer, i, p. 150, pi. 

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



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

 is distinguished by the peculiar sculpture of the shell. 



R. LACTEA Jeffreys. Unfigured. 



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

 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 striae 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 im 

 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 



