FUSUS. 323 



above low- water mark, and its bathymetrical range pro- 

 bably extends to the yet "unsounded deeps/' The 

 egg-cases of Fusus are membranous, double-sheathed, 

 semioval or hemispherical, and attached by their base : 

 in F. antiquus they are agglomerated (as in Buccinum 

 undatum) ; but in the other British species they are 

 separate, and resemble those of Trophon. The tongue 

 is enclosed in a sheath of muscular fibre. According 

 to Loven the odontophore of F. antiquus agrees with 

 that of B. undatum, and differs from F. gracilis and F. 

 Berniciensis in having the central tooth broader across, 

 with the front margin extended on each side in a trun- 

 cated form ; while in the last two species it is squarish. 

 Judging, however, from drawings, kindly furnished by 

 my friend Mr. Alder, of this apparatus in seven of our 

 native species, the plan of construction varies consider- 

 ably in all but F. Islandicus, F. gracilis, and F. propin- 

 quus, the odontophores of which are similar. 



Klein was the original author of the name Fusus ; 

 but he applied it to a large group which he called a 

 genus, each of his species containing several modern 

 genera. Bruguiere's definition was likewise too exten- 

 sive ; and Lamarck restricted this genus to nearly its 

 present limits. The species are apparently peculiar to 

 the northern hemisphere. 



A. Sculptured only by slight spiral ridges or striae. 



1. Fusus ANTIQUUS*, Jjinne.) ty.tr. 



Murex antiquus, Linn. S. N. p. 1222. F. antiquus, F. & H. iii. p. 423, 

 pi. civ. f. 1, 2. 



BODY whitish or yellowish-white, with a faint tinge of 

 fleshcolour, sometimes partially speckled with black : pallial 



* Of great antiquity, regarding it as also fossil. 



