1884.] 'lightning' and 'porcupine ' expeditions. 343 



l 2. ACLIS SUPRANITIDA, S. Wood. 



Alvania supranitida, S. Wood, Cat. Crag. Moll. 1842. 



Aclis supranitida, B. C. iv. p. 103, pi. ii. fig. 4. 



'Porcupine' Exp. 1869: St. 18, Donegal Bay (fine and living 

 specimens), N. Channel. 1870: Atl. Vigo Bay; Med. 30, 55, 

 Adventure Bank. 



Distribution. W. Norway to the Mediterranean and Adriatic, 

 Madeira and Canaries (Mc Andrew) ; 8-108 fms. 



Fossil. Pliocene : Coralline Crag and Italy. Post-tertiary : Nor- 

 way (Crosskey and Robertson), Belfast (Stewart). 



The synonyms are referable not only to Aclis, but also to Tur- 

 ritella, Alvania, and Pyramis, with various specific names ; for these 

 see ' British Conchology.' 



The following is an extract from my note-book as to the Donegal 

 Bay specimens : — " Body clear white, with a pink streak down the 

 middle : mantle rather thin : snout or mentum bilobed in front : 

 tentacles triangular (being a modification of those in Odostomia), 

 with blunt tips : eyes 2, black, small, sessile on the head at the inner 

 base of the tentacles : foot elongated, squarish in front and pointed 

 behind : operculum thin, striated in the line of growth ; spire small, 

 placed close to the inner or pillar lip." 



Sculpture of the shell very variable, sometimes altogether wanting. 



3. Aclis walleri, Jeffreys. 



A. walleri, B. C. iv. p. 105 ; v. p. 210, pi. Ixxii. fig. 4. 



'Porcupine' Exp. 1869: St. 15, 19, 36, 47. 1870: Atl. 3, 6, 

 9, 16, 17, 17a; Med. Adventure Bank. 



Distribution. ' Voringen ' Arctic Expedition and Loffoden Isles to 

 the Gulf of Egina, New England (Verrill), off C. Verd I. ('Talis- 

 man' Exp.); 10-1192 fms. 



Fossil. Pliocene : Coralline Crag, Calabria, and Sicily. 



Synonyms. A. terebralis, M. Sars, MS., var. minor as A. eccigua, 

 G. O. Sars, and Odostomia nisoides, Brugnone. Monterosato prefers 

 to spell the specific name " valleri" ; but it is evident that, although 

 there is no letter W in the Latin language, it would not be right to 

 alter the name in order to put it into a classical dress, and the 

 identification of valleri with the name of the discoverer of the 

 present species would be lost. 



This pretty shell is very variable in size as well as in sculpture. 

 Some specimens from the 'Porcupine ' Expedition of 1870 show in- 

 distinct traces of spiral ridges on the last whorl and of longitudinal 

 ribs on the upper whorls, while others have a slight keel on the 

 periphery. But not one of these characters is constant. M. Bour- 

 guignat, indeed, says, in his second letter to Professor Brusina 

 ('Lettres malacologiques,' Paris, 1882, pp. 36-38), " La nouvelle 

 ecole distingue done, sur un nom special, toute forme ayant des 

 caractbres constants, pourvu que ses caracteres soient au nombre de 

 trois. Au-dessous de ce nombre elle rejette les formes au rang de 

 variete." The words italicized are similarly emphasized in the 



