208 SCALARIADiE. 



The operculum is ratlicv concave, ovate, with three 

 vohitions terminating in a nearly central nucleus. 



The animal (which was long ago examined hy Mr. 

 Clark) has a short and broad head, with a vertically 

 cleft centre, from which it protrudes frequently a long 

 thick white retractile proboscis. The tentacles are long 

 and slender, with eyes at their external angles on very 

 slight bulgings, or nearly immersed. The foot is narrow, 

 subtriangular, grooved beneath throughout its length, and 

 bears on its caudal extremity a subspiral dark horny 

 operculum, on a thin membranous lobe. The colour of 

 the head, tentacles, and upper part of the foot, is blackish 

 grey, mingled at the margins of the foot (which is white 

 beneath) with a few white or pale yellow specks. Mr. 

 Alder describes a specimen taken alive by him at Torbay, 

 as having black tentacles, Avitli the eyes on white spaces 

 at their external bases, the head streaked above with black, 

 as also the foot, which is slightly grooved down the centre. 

 The operculigerous lobe is large and produced at the sides. 



This, though widely distributed, is a scarce species. 

 Tn the main it is southern ; Margate (S, H.) ; and a 

 single specimen from the fishing-boats at Cullercoats (Fryer, 

 fide Alder), are instances of its occurrence on the east 

 coast. Torquay (S. H.) in seven fathoms ; Dartmouth 

 (M'Andrew and E. F.) ; Exmouth (Clark) ; Plymouth, 

 Shellness, North Devon, Tenby, Swansea (Jeffreys) ; 

 Torbay (Alder) ; on both east and west of Ireland 

 (Thompson) ; Cork (J. D. Humphreys) ; Jiantry Hay 

 (Jeffreys) ; Birterbuy and Arran in Galway (Barlee). 

 A coloured variety with sharper ridges has been found 

 near Swansea (Jeffreys) ; and at Exmouth (Clark). 



It ranges to the Mediterranean, and is enumerated 

 among Scandinavian species by Loven. 



