ZOOLOGY 



MARINE ZOOLOGY 



An account of the marine fauna of Devonshire is of necessity linked with 

 the history of Marine Zoology in the British Isles. This connexion is 

 probably due to the exceptional richness of a fauna which attracted the 

 attention of many of the foremost naturalists of the nineteenth century. 

 Among those who have published papers embodying information derived 

 from the study of the marine fauna of Devonshire may be mentioned: 

 Alder, Clarke, Couch, Cocks, Spence Bate, Gosse, Hincks, Montagu, Norman, 

 and Parfitt. Many papers have also been published in the Association's 

 Journal by workers at the Plymouth Laboratory of the Marine Biological 

 Association. 



The richness of the fauna being due chiefly to the very varied nature of 

 the shore between tidemarks and of the bottom deposits in deeper water, 

 a short sketch is given of the conditions prevailing in the more important 

 estuaries and bays, and on the various trawling and dredging grounds off shore. 



Of the former, Plymouth Sound, an arm of the sea, into which the 

 estuaries of the Plym and Tamar open, is by far the most important and at 

 the same time the most varied. 



The shores round Plymouth Sound are for the most part rocky, with 

 sand, mud, and gravel between the rocks. The latter vary in character and 

 formation on different parts of the shore ; being shale at Rum Bay, limestone 

 under the Hoe, grit at Drake's Island, etc. Patches of sand are occasionally 

 met with, the most productive being at Batten and Drake's Island, but there 

 are no long stretches of sandy beach. In the estuaries of the Plym and 

 Tamar the shore at low water is composed of mud, sand, or muddy gravel. 



The bottom deposits of the Sound itself consist chiefly of fine muddy 

 sand, with shoals of stones with mud, whilst honeycombed stones are to be 

 found in Millbay Channel, and clean stones and shell gravel between Drake's 

 Island and the west end of the breakwater. The latter is composed of large 

 masses of limestone, which on the north side form a favourite collecting 

 ground. The Church Reef in Wembury Bay, and the Reny Rocks between 

 this and Bovisand Bay, are two reefs of rock with boulders. Rock pools 

 are fairly numerous under the Hoe, in Wembury Bay, among the Reny 

 Rocks, and on Drake's Island. 



The shores of the Yealm River consist of mud, sand, and muddy gravel 

 banks, with occasional patches of Zostera, whilst the bottom deposits in the 

 channel are sand, with Zostera at the mouth, and stones and shells higher up. 

 At Salcombe, the shore high up the estuary above the Salstone is fine mud ; 

 from the Salstone to Snapes Point it is chiefly muddy gravel, whilst below 

 Snapes Point it is almost entirely fine sand with several Zostera banks. The 

 deposits in the channel above Snapes Point are chiefly fine sticky mud, with 

 stones ; round Snapes Point, clean shell gravel, and below this point stones 

 and shells, whilst at the mouth of the harbour, on the bar, they are fine sand. 



131 



