1833.'] 'lightning' AND ' PORCUPINk' EXPEDITIONS. 89 



part of the body- whorl : umbilicus rather large, funuel-shaped, and 

 deep : operculum not observed, the specimens now described being 

 dead. L. 0-1. B. O'l. 



'Porcupine' Exp. 1870: Atl. St. 16, 1/, 1/a. Several speci- 

 mens, more or less perfect. 



This differs from any other species known to me in being devoid 

 of sculpture, and iu having a conspicuous umbilicus. 



3. ScissuRELLA cosTATA, d'Orbigny. 



S. costafa, d'Orb. Mem. Soc. d'hist. nat. de Paris, i. p. 344, 

 t. xxiii. f. 2. 



' Porcupine ' Exp. 1870 ; Atl. St. Tangier B. 



Distribution. Throughout -the Mediterranean and Adriatic, Ma.- 

 deira. (Watso7i), Teneriffe (McAndrew) ; 0-11 fms. 



Fossil. Pliocene : Italy, Rhodes. 



S. plicata and S. striatula, Philippi, besides several obsolete 

 synonyms. 



S. Icevigata of d'Orbigny is apparently a variety. 



Family VII. Trochid^. 



\/ 1. MOLLERIA COSTULATA, Moller. 



Margarita'^ costulata, Moll. Ind. Moll. Gronl. p. 8. 



Molleriu costulata, B. C. iii. p. 291 : G. O. Sars, Moll. reg. arct. 

 norv. p. 127, t. 9. f. 8, a~c. 



'Lightning' Exp., St. 2. 



'Porcupine' Exp. 1870: Atl. 17. 



Distribution. Arctic seas in both hemispheres, eastern coasts of 

 N. America, Bay of Biscay (' Travailleur ' Exp. 1880), St. Thomas, 

 W. Indies {Verkruzen) ; 0-150 fms. 



Fossil. Post-tertiary: Scandinavia, Shetland, Scotland, co. Antrim, 

 Canada ; 0-460 ft. 



This genus is distinguishable from Cyclostrema by having a double 

 inside lip or a ledge to receive the strong calcareous operculum. 

 The sculpture also is peculiar. I described the animal of M. costu- 

 lata in the ' Annals and Magazine of Natural History ' for March 

 1877. The odontophore has been figured by Eriele. 



Margarita minutissi?na of Mighels, and Skenea wolleri of Phi- 

 lippi. 



(/ 2. MoLLERiA LEViGATA, Jeffreys. 



Mollerin lavigata (Jeffr.), Friele, Bidrag til Vestlandets Mollusk- 

 fauna (Vid. Forh. 1875), p. 4 ; separate copy. 



Cijclostrema Icevigatum, G O. Sars, Moll. reg. arct. uorv. p. 130, 

 t. 21. f. 2, a-h. 



'Lightning' Exp., St. 5, 6. 



Distribution. Finmark (G. O. Sars), Bergen coast (^Friele, Nor- 

 man, and J. G. J.), Shetland {J. G. J.) ; 20-250 fms. 



Fossil. Pliocene : Sicily. 



Cyclostrema basistriatum of Brugnone ; but in a copy of his 



