1883.'] ' lightning' AND 'porcupine ' EXPEDITIONS. 89 



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

 deep : operculum not observed, the specimens now described being 

 dead. L. 01. B. O'l. 



•Porcupine' Exp. 1870: Atl. St. 16, 17, 17«. Several speci- 

 mens, more or less perfect. 



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

 of sculpture, and in 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 {Watson'), Teneriffe (AIcAndrew) ; 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. Trochxd^. 



\/ 1. MoLLERIA COSTULATA, Mollef. 



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 minutissima of Mighels, and Skenea molleri of Phi- 

 lippi. 



1/ 2. MoLLERiA LEViGATA, Jeffreys. 



Molleria Icevigata (Jeffr.), Friele, Bidrag til Vestlandets Mollusk- 

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



Cyclostrema Icevigatum, G O. Sars, Moll. reg. arct. norv. p. 130, 

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



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



Distribution. Finmark {G. O. Sai's), Bergen coast (Friele, Nor- 

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



Fossil. Pliocene : Sicily. 



Cyclostrema basistriatum of Brugnone ; but in a copy of his 



