318 Dr. Gwyn Jeffreys on 



way, 50-400 fms. (Lov^n and others). ' Porcupine' Expedi- 

 tion, 1869, 64-134 fms.: 1870, English Clianncl, 358- 

 690 fms. ; Mediterranean, 1456 fms. iEgean, 310 fms. 

 (Spratt) ! Palermo, 210 metres = nearly 114 fms. (Monte- 

 rosato). Gulf of St. Lawrence, 166 fms. (Whiteaves) ! 



Naticidae. 

 Natica ajfiins, Gmelin. 

 Nerita affinis, Gm. Linn. Syst. Nat. ed. 13, p. 3675, 

 Body yellowish-white, with fine streaks of purple at the 

 upper sides of the foot : mantle thick, folded over the umbi- 

 licus or basal cavity of the shell : tentacles conical and pointed, 

 turned back on the front edges of the shell at its mouth : 

 eyeSj none observable : foot large, roundish-oval. 



Variety occlusa. 



Natica occlusa, S. V. Wood, Mon. Crag Moll. "(1848) p. 14G, tab. xii. 

 f. 4a, b ; Suppl. (1872) p. 70, t. iv. f. 11. 



Body pale yellowish, with a purplish tinge or slight streaks 

 of the latter colour on the back of the foot : head large, hood- 

 shaped, indented in the middle : mantle thick, spread over the 

 back of the shell : tentacles conical and finely pointed, wide 

 apart, and separated by a rather thin veil : ei/es, none percep- 

 tible : foot enormous and very voluminous, broad and cloven 

 in front, expanding greatly on each side, and rounded behind. 



Variety vittata. 



Body milk-white : head forming abroad and bilobed snout : 

 tentacles conical, pressed by the head-flaps against the front 

 of the shell, and for the most part concealed ; tips pointed : 

 eyes not to be detected : foot large, thick and broad, folded 

 inwards at the sides, rounded in front, and bluntly pointed 

 behind. Sluggish. Floats with its foot uppermost. 



Godhavn, 5-20 fms. ; Station 4, 20 fms. (var. vittata : 

 globosa, spira extensa, vittis duabus purpureis distantibus ulti- 

 raum, una cum penultimo, anfractum cingentibus) ; 5, 57 fms. 

 (var. occlusa) ; Holsteinborg, 12 fms. (var. vittata) and 35 fms. ; 

 Station 7, 1100 fms. (fragment) ; 13, 690 fms. (operculum). 

 Arctic seas, in both hemispheres, and Norway, 20-450 fms. 

 'Porcupine' Expedition, 1869, 74—345 fms. (var. lactea: 

 minor, ovata, alba, spira extensa) : 1870, coast of Portugal, 

 994 fms.; Mediten-anean, Adventure Bank, 92 fms. (young). 

 One of the most common and characteristic fossils of the 

 newer Tertiary and Quaternary formations in the north of 



