OF NORTHUMBERLAND AND DURHAM. 11 



MM, Audouin and Milne Edwards, who first proposed the dis- 

 tribution of marine animals into zones of depth,* have adopted 

 much smaller divisions, and it would be easy to point out the 

 limits of species, especially between tide marks, within much 

 more contracted bounds, but the above broad and well-marked 

 features are sufficient for our present purpose. Those species 

 which from their numbers give a character to the zone, we have 

 denoted by italics ; those which from their rarity or partial dis- 

 tribution in Britain give a character to the locality, are distin- 

 guished by small capitals. 



Littoral Zone. — Doris tuberculata, repanda, hilamellata, as- 

 pera; Goniodoris nodosa; Ancula cristata ; Eolis papillosa* 

 NANA ; Odostomia spiralis ; Littorina petrsea, rudissima, 

 rudis, littorea, retusa ; Eissoa interrupta, ulvfe ; Lacuna 

 pallidula ; STcenea planorhis; Troclms cinerareus ; Purpura 

 lapillus; Coriocella tentaculata ; Patella vulgata; Chiton 

 margmatiis: Modiola discrepans ; Mytilus edidis ; Pullastra 

 vulgaris, perforans ; Kellia suborbicularis ; Mya truncata, 

 arenaria; Pholas crisjmta, Candida; Cynthia rustica; Ascidia 

 depressa ; Botryllus Schlosseri, rubens ; Botrylloides Leachii. 

 Laminarian Zone. — Dendronotus arborescens ; Eolis olivacea, 

 coronata, rufibranchialis, picta ; Amphisphyra hyalina, 

 Rissoa parva, striata, semistriata ; Lacuna vincta, var. 

 quadrifasciata ; Margarita helicina; Turritella terebra ; 

 Fusus turricula ; Pleurotoma linearis, rufa ; Buccinum un- 

 datum, var. 3; Nassa incrassata; Cyprcea Europea ; Velu- 

 TiNA PLiCATiLis j Lottla virginea; Patella pellucida, Isevis; 

 Chiton fascicularis, ruber; Modiola discrepans; Cardium 

 edule ; Venus gallina ; Tellina tenuis, fahula ; Syndosmya 

 alba ; Mactra stultorum ; Solen siliqua, ensis. 

 Coralline Zone. — Polycera Lessonii ; Tritonia plebeia ; Doto 

 fragilis, coronata; BuLL^ffiA pectinata, quadrata ; Bulla 

 Cranchii, cylindracea; Scalaria Trevelyana; Odostomia 

 interstincta; Rissoa inconspicua, punctura; Trochustumidus; 

 Fusus antiquus, gracilis, propinquus, clathratus ; Buccinum 



* Recherches pour eervir a V Histoire Naturelle du Littoral de la France, 

 V. i., p. 235. 



C 



