Explanation of the Plates. 
Plate I. Fig. 1: The earlier bottom-sampler on pole. Figs. 2 and 3: A recent model of the 
0., m.” bottom sampler; open (2) and closed (3). All the figures much reduced. 
— II. The commonest animals on the soft bottom in Thisted Bredning. All figures in the 
natural size. 
Fig. 1. Trochus cinerarius. Fig. 15. Cyprina islandica. 
»… 2. Nassa pygmæa. »… 16. Mya truncata. 
214373. >» reticulata. >» 16ab. » > The sizes eaten 
»… 4. Buccinum undatum. by plaice. 
»… 5. Littorina littorea. »… 17. Aphrodite aculeata. 
»… 6. Acera bullata. »… 18. Nephthys coeca. 
>». 7. Philine aperta. >». 19. Pectinaria belgica. 
»… 8. Abra alba. »… 20. Gammaridæ. 
»… 9. Cardium fasciatum. »… 21. Diastylis Rathkii. 
»… 10. Macoma baltica. » 22. Idothea. 
»… 11. Nucula nitida. »… 23. Ophioglypha texturata. 
>» 12. Solen pellucidus. » 24. Asterias rubens. 
>» 13. Corhula gibba. »… 25.  Echinocyamus angulosus. 
>» 14. Mytilus edulis. »… 26. Echinus miliaris. 
— III. 0,, m.” of sea-bottom in Thisted Bredning with its average fauna. Natural size. 
191, 1910. (see Table V). 
— IV. 0…, m.? of sea-bottom in the Kattegat, west of Håganæs. ””/, 1910. (see Table VI). 
— V. 0… m.” of sea-bottom in Holbæk Fjord and Bramsnæs Vig. '/, 1910. (see Table VI). 
— VI. 0…, m.” of sea-bottom in the Baltic. E. S. E. of Høje Møen. ”/, 1910. (see Table VI). 
The Plates III—VI have been drawn schematically to represent the density of the 
population on the sea-bottom; each represents 50 x 50 cm. = 0.,, m.” of sea-bottom, natural 
size, with the average fauna belonging thereto in natural size. On such a small space of sea- 
bottom it is impossible to reproduce exactly the mass of the fauna; often only a portion of an 
individual of a species should be represented; to counterbalance this I have sometimes combined 
nearly related forms to one individual, or have represented a small individual, so as to come 
as near as possible to the portions found; these difficulties naturally occur most often in the case 
of the least frequent species. Reference may further be made to the text, especially the section 
on: The mass and composition of the bottom-fauna at several places in Danish waters. 
It would be of interest from a biological standpoint to have such quantitative pic- 
tures made of a large area of the sea-bottom; this is not possible in natural size on Plates; 
it might be done in biological museums. 

