OF NORTHUMBERLAND AND DURHAM. 105 
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. 
LarroraL Zonz.—Doris tuberculata, REPANDA, bilamellata, as- 
pera; Goniodoris nodosa; Ancula cristata ; Holis papillosa, 
NANA; Odostomia spiralis ; Littorina petra, srudissima, 
rudis, littorea, retusa; Rissoa interrupta, ulve ; Lacuna 
pallidula ; Skenea planorbis; Trochus cinerareus ; Purpura 
lapillus; Coriocella tentaculata; Patella vulgata; Chiton 
marginatus; Modiola discrepans; J/ytilus edulis; Pullastra 
vulgaris, perforans ; Kellia suborbicularis ; Mya truncata, 
arenaria; Pholas crispata, candida; Cynthia rustica; Ascidia 
depressa ; Botryllus Schlossert, 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; Massa incrassata; Cyprea Europea ; VEuu- 
TINA PLICATILIS ; Lotta virginea; Patella pellucida, levis; 
Chiton fascicularis, ruBER; Modiola discrepans; Cardium 
edule ; Venus gallina; Tellina tenwis, fabula ; Syndosmya 
alba ; Mactra stultorum ; Solen siliqua, ensis. 
CoraLLineE Zone.—Polycera Lessonii ; Tritonia plebeia ; Doto 
fragilis, coronata; BULLHA PECTINATA, QUADRATA; BuLLA 
Crancuu, cylindracea; ScaLaRIA TREVELYANA; Odostomia 
interstincta; Rissoa inconspicua, punctura; Trochustumidus; 
Fusus antiquus, gracilis, PRopINQUUS, clathratus ; Buccinum 
* Recherches pour servir Al’ Histoire Naturelle du Littoral de la France, 
V. i, p. 235. 
VOL. I. P 
