186 THE FAUNA OF THE SALCOMBE ESTUARY. 



from an inch to three or four inches beneath the surface of fine mud. 

 The anemone attaches itself to the stones or gravel, the body becomes 

 often much elongated, and the disc is protruded and expanded above 

 the surface of the mud. In some places the mud-banks are carpeted 

 with these expanded discs, which may be seen before the tide has 

 quite left the bank. When the bank is dry the discs of the anemone 

 are contracted, and what appear to be a number of holes are seen 

 in the mud. This condition of things is found especially in the 

 Kingsbridge estuary — on the Salstone and on the shore between Halwell 

 Point and Pilworthy Point large patches of ground suitable for the 

 species exist — and is also frequent at the north-east end of Salcombe 

 Harbour. In the parts of the harbour nearer the mouth the anemone 

 often occurs on the banks, but is never met with in such abund- 

 ance as in the upper parts of the estuary. Gosse {British Anemones, 

 p. 33) describes what appears to be a similar condition of things to 

 that found on the mud-banks at Salcombe, in the Fleet and the 

 Backwater at Weymouth, though he says that the anemone simply 

 rests on the mud with its broad, flat base. This is certainly not the 

 case in the Salcombe estuary, nor is it so in the Paver Yealm, near 

 Plymouth, where we also meet with the same phenomenon. Further, 

 Gosse speaks of the Weymouth specimens as a " breed of the species " 

 which deviates from the " normal habit." It would, we think, be more 

 correct to say that the "normal habit" of the species is to live in 

 the estuarine mud-flats. This is where its centre of distribution is 

 to be found, whilst individuals of the species extend to suitable and 

 sheltered situations in the rock-pools along the more open coast. As 

 has already been pointed out by one of us,* it is of primary importance, 

 when considering the adaptation of species to their environment, that 

 the true centre of distribution of the species should be known, for it is 

 to the conditions there prevailing that the species is best adapted, and 

 it is there that the species is kept true. 



Sagartia parasitica {Couch). Found in the usual position, namely, 

 on the shell inhabited by Eupagurus hernhardus. On the shore at 

 Salstone, and dredged from the channel between Salstone and Snape's 

 Point. 



Adamsia palliata {Bohadsch). Dredged in the channel between 

 Salstone and the mouth of Salcombe Harbour. Commensal with 

 Eupagurus Prideavxii. 



Anthea cereus, Ellis and Solandcr. Living on the rocks at the 

 mouth of Salcombe Harbour and also in the channel of the harbour 

 itself, where it was dredged. 



• Jonrn. Mai: Biol. Assoc, vol. v. 1899, pp. 367 and 473, 



