236 FISH. BIRDS. MAMMALS. 



were, however, still living in the Isefjord at the beginning of 

 this century, and their destruction cannot be altogether ascribed 

 to the fishermen, as great numbers of dead shells are still 

 present ; but in this case it is attributed to the abundance of 

 starfishes, which are very destructive to oysters. On the 

 whole, their disappearance, especially when taken in connection 

 witli the dwarf size of the other species, is evidently attribut- 

 able in a great measure to the smaller proportion of salt in 

 the water. 



Of Crustacea, only a few fragments of crabs have hitherto 

 been found. The remains of vertebrata are very numerous 

 and extremely interesting. In order to form an idea of the 

 number of bones, and of the relative, proportions belonging 

 to different animals, Professor Steenstrup dug out from three 

 different parts of the shell-mound at Havelse, square pillars 

 with sides three feet in length, and carefully collected the 

 bones therein contained. In the first pillar he found 175 

 bones of mammals and 35 of birds ; in the second pillar he 

 found 121 of mammals and 9 of birds; in the third, 309 of 

 mammals and 10 of birds. The pillars, however, were not 

 exactly comparable, because their cubic contents depended on 

 the thickness of the shell-mound at the place where they were 

 taken, and varied between seventeen and twenty cubic feet. 

 On the whole, Professor Steenstrup estimates that there were 

 from ten to twelve bones in each cubic foot. It will be seen, 

 therefore, that the number of bones is very great. Indeed, 

 from the mound at Havelse alone the Committee obtained in 

 one summer 3500 bones of mammals, and more than 200 of 

 birds, besides many hundred of fishes, which latter, indeed, 

 are almost innumerable. The most common species are 



Clupea harenyus, L. (the herring), 



Gadus callarias, L. (the dorse), 



Pl&wronectes limanda, L. (the dab), and 



Murcena anyuilla, L. (the eel). 



