156 THE FAUNA OF THE SALCOMBE ESTUARY. 



III. Description of the Fauna found in different parts of the 

 Salcombe Estuary. 



1. THE SALSTONE. 



[Shore collecting : July 13tli, 1900, tide 15 ft.; July SOtli, 1900, tide 14 ft. 5 in.; 

 August 12tli, 1900, tide 16 ft. ; October lOtli, 1900, tide 16 ft. 8 in.] 



The Salstone (see Chart) lies some distance up the Kingsbridge 

 estuary, at the mouth of Frogmore Creek, and is distant about 2 miles 

 from the Blackstone, which guards the entrance to Salcombe Harbour 

 proper. It is completely covered for a short time at high tide, but is 

 generally to be seen as an island standing almost in the middle of the 

 estuary. The main channel of the Kingsbridge river passes close to 

 its western side, whilst the water from Erogmore Creek passes down 

 the south-east shore. These two shores, the western and south-eastern, 

 from half-tide mark to low water, have a soil composed of hard muddy 

 gravel, which only covers the underlying shale with a layer a foot or 

 eighteen inches deep. At the southern end of the Salstone there is a 

 small stretch of clean, coarse sand uncovered at extreme low water 

 (16 ft. 8 in. tide). 



The north-east shore, which is sheltered from the main tidal streams, 

 is on the other hand covered with soft, sticky mud, so soft that one can 

 only walk ou it with very considerable difficulty. 



On the muddy gravel of the western and south-eastern shores the 

 common and characteristic animals are : — 



(1) Fixed Species. Morchellium argus, which is present on the 

 muddy gravel in exceptional abundance ; the orange-coloured sponge, 

 Hyincniacidon sanguineum, also very common ; Sagartia hellis, numerous 

 in patches where a layer of mud lies on the top of a layer of gravel ; 

 Myxicola ivfiindihulum, whose gelatinous tubes are very frequent, 

 especially at the lowest tidal levels; Branchiomma vesiculosum, the 

 tubes of which occur fixed often in clusters in the muddy gravel, but 

 are confined almost entirely to the tidal level which is only just 

 uncovered at a 15 ft, tide; Sahella 2Jnvonina, which on the south-east 

 shore is found in bunches of twenty or thirty together at a lower tidal 

 level than the Branchiomma, namely that just exposed at a 16 ft. tide; 

 Clavclina lepadiformis, frequently attached to some of the larger stones, 

 especially on the western shore; and Melinna adriatica, which is 

 often met with in muddy patches, though it cannot be called plentiful 

 and must be regarded as an immigrant from the adjoining fine mud. 



