ILLUSTRATIONS. XIII 



An intensive study of fauna and flora of a restricted area of sea bottom — Continued. page. 



Fig. 15. Local distribution of the " whelk," Buccinum uiidatum 1251 



16. Local distribution of the common scall'^p, Pccten gibbus borealis 1252 



17. Local distribution of the "smooth" or northern scallop, Pecten magcllanicus i-53 



18. Local distribution of the common purple sea-urchin, Arbacia punclHlata 1254 



19. Local distribution of the green sea-urchin, Sirongylocentrus drobachiensis 1255 



20. Local distribution of the common starfish, Asterias jorbesi 1256 



21. Local distribution of the purple starfish, Asterias vulgaris 1257 



22. Local distribution of the " boat shell," Crepidula jornicata 1258 



23. Local distribution of Crepidida convexa, a smaller species than the preceding i-59 



24. Local distribution of the hermit crab Pagurus longicarpus 1260 



25. Local distribution of the liermit crab Pagurus poUicaris 1261 



26. Local distribution of the hermit crab Pagurus annulipes 1262 



27. Local distribution of the hermit crab Pagurus acadtanus 1263 



Gases dissolved in the waters of Wisconsin lakes: 



Fig. I. Sketch map of Wisconsin, showing lake districts 1276 



2. Lake Mendota. Chart showing vertical distribution of gases, carbonates, and tem- 



perature, January 26, 1906 1-77 



3. Lake Mendota. Same, February 25, 1906 1278 



4. Lake Mendota. Same, March 29, 1906 i-79 



5. Lake Mendota. Same, ."^pril 8, igo6 1280 



6. Lake Mendota. Same, May 4, 1906 1281 



7. Lake Mendota. Same, May 22, 1906 1281 



8. Lake Mendota. Same, July 2, 1906 1282 



9. Lake Mendota. Same, August i, 1906 1283 



10. Lake Mendota. Same, October 8, 1906 1284 



11. Lake Mendota. Same, October 1 1, 1906 1285 



12. Green Lake. Same, October 4, 1906 1286 



13. Lake Geneva. Same, September 26, 1907 1287 



14. North Lake, east part. Same, July 30, 1906 1288 



15. Thousand Island Lake. Same, .'\ugust 13, 1907 1289 



16. Stone Lake. Same, August 22, 1907 1289 



17. Beasley Lake. Same, .\ugust 4, 1908 ■ 1290 



18. Otter Lake. Same, August 4, 1908 1290 



19. Silver Lake. Same, August 21, 1907 1291 



20. Hammills Lake. Same, August 17, 1908 1291 



Volumetric studies of the food and feeding of oysters; 



Fig. I. Design of water-specimen cup, elevation 1300 



2. Same, section 1300 



3. Same, cross section at A, figure 2 1301 



4 and 5. Same, details of tripping device 1301 



6. Apparatus for extracting contents of alimentary tract of oysters 1305 



Plan for an educational e.xhibit of fishes. 



Fig. I. Plan of fish hall in American Museum of Natural History, illustrating "corridor 



method " of arranging cases 1 320 



2. Example of family label 132 1 



3. Example of popular label for individual specimens 1322 



4. Example of descriptive case-label defining a suborder i3-4 



5. An accessory label to illustrate a biological phenomenon 1325 



6. Plan showing hall adapted to the "alcove arrangement" of cases 1326 



7. Diagram of fish case to be used in hall with "alcove arrangement" i3-7 



8. Plan illustrating "gallery arrangement" of fish exhibits 1328 



9. Sketch illustrating combination of pictorial fish groups with synoptic method of ex- 



hibition 1 329 



