106 ANALYTICAL INDEX. 



CHAPTER n.— continued. 



FLATTENED SPIRAL TESTACEA, . . page 47 



Singular arrangement of nature, , . . ib. 



Everything harmonious in nature, ... ib. 



The Ammonites, . . . . . ib. 



Planorbis inconspicua, .... ib. 



Minute figure and animal described, . . . ib. 



Colour, &c., ..... ib. 



Planorbis Spirorbis, . . . .48 



Shell and animal described, ... ib. 

 Pulsation, ...... ib. 



Food, ...... ib. 



Motions, &c., . . . . . ib. 



Instances of its tenacity of life, ... 49 



Spawn in March, . . . . .50 



Experiments in 1820, . . . . ib. 



Planorbis rhomeeus, . . . . ib. 



Shell and animal described, ... 51 



Food, the Equisetum, cj'c, . . . . ib. 



Specimens from Coldingham Loch, . . ib. 



Planorbis carinatus, . . . .52 



Shell and animal described, ... ib. 



Unexplainable peculiarities, . . . . ib. 



Feeds on the common pond weed, &c., . . ib. 



Planorbis imbricatus, . . . .53 



Diameter of the shell, &e., ... ib. 



Animal a Limax, . . . . . ib. 



Feeds on vegetable substances, ... ib. 



Spawns in February and May, . . . ib. 

 Plate XL described, . . . 51,52,53 



Valvata obtusa, .... ib. 



Resembles the Helixes of the field, &c., . . ib. 



Shell and animal described, ... ib. 

 Colour bluish grey, ..... 54 



Feeds on the Equisetum, .... ib. 



Vivacious — dwells in lakes and tranquil streams, . ib. 



Either different species or great varities of this animal, ib. 



Spawns in August, . . . . . ib. 



ProgrcbS of spawning described, ... 55 



