of the Fishery Board for (Scotland. 347 



of May and June, a close time is practically adopted, and the clams get 

 rest from the almost daily presence of the dredge. During the colder 

 months of the year, beginning with the month of October, clam dredging 

 is pursued more vigorously than in summer, and the quantities landed in 

 winter are greatly in excess of those obtained in the warmer months. It 

 has already been mentioned that one class of boats dredge clams for sale 

 to the large fishing boats that proceed to the banks east of the May, while 

 other boats, which are engaged in long-line fishing within the Firth, secure 

 the clams to bait their lines as they return from the fishing ground. In 

 both kinds of boats, the dredge used is an oyster dredge of five or six 

 feet breadth of mouth. The net attached to the mouth-frame is, on the 

 lower side, made up of a series of lacing iron rings, and, on the uppe&side, 

 it is composed of ordinary twine network. Such an arrangement of iron 

 netting, on the side of the bag that is dragged along the bottom, prevents 

 holeing of the net by the sharp valves of the scallop. The length of 

 dredge rope { paid out ' is regulated by the speed at which the boat is moving 

 and the depth of the water. Whether the dredge is securing a selection 

 from the animals living on the bottom is easily ascertained by the presence 

 or absence of the characteristic pulse with which every worker at dredging 

 is familiar. When the boats dredge right over the banks, and not merely on 

 their edge, if there is plenty of wind to propel boat and dredge, a short 

 time suffices to obtain a dredgeful of clams. When the contents of the 

 dredge are emptied into the boat, a process of selection takes place, the 

 fully grown scallops being separated from the smaller and younger 

 individuals. The latter are returned to the sea, as is all that remains of 

 former generations of clams, viz., the dead shells. The policy of returning 

 the shells to the sea is good, as it makes the muddy ground more suitable 

 as a habitat for the living, supplies the young with a firm object for attach- 

 ment, and returns gradually to solution the salts of lime which the shell- 

 gland and the mantle of the animal secreted from the sea water. 



Living in close association with the scallop is the horse-mussel (Mytilus 

 modiolus). The beds, judging by the quantities of these obtained on the 

 southern bed at each haul, are strewn with these bivalves. The horse- 

 mussels attach themselves to each other and to other objects by ' byssus 

 threads ' which act much the same part as does the * bent ' of sandy dunes. 

 This coarse grass, by its branching rootlets and stems, binds together the 

 sand, which otherwise would be carried about and shifted during every 

 storm. So the ' byssus threads ' link mussel, shells, stones, and sand, and 

 make firm the loosely aggregated particles of such a bed as this. The 

 horse-mussels, therefore, are eminently helpful to the clam, for they afford 

 a firm basis of attachment for the young and a foothold for the adult to 

 maintain its position in spite of adverse currents. Some such bivalve as 

 the horse-mussel is absolutely essential to the growth of the beds in the 

 Forth to ensure that the fine mud does not bury the clams, and as a result 

 kill them. 



A few oysters are obtained by the boats, and near Inchkeith vast 

 quantities of dead Turritella shells are brought up by the dredge. Very 

 large Actinix, many specimens of Alcyonium palmatum, Zoophytes, 

 including Hydroids and Polyzoa, a few of Biiccinum undatum, compara- 

 tively few Ascidians, but many Sponges live alongside of the bivalves on 

 the bed. Large numbers of Anomia ephippium, so often popularly 

 mistaken for the young of the true oyster, some of the hermit crabs, an 

 odd Polynoe and Nemertean, and the ubiquitous Echinoderms are there. 

 Of the last the Ophiurids are in greatest abundance, and the common star- 

 fish (Uraster rubens) is much rarer than its 12 to 15-fingered relative 

 (Solaster papposus) \ Cribella and Echinus sphxra are also present. 



