Mollusca, 



CEPHALOPODA. 



India, and China Ink Fossil ink-bags Octopus vul- 

 garis The colour " Sepia" Sepia qfficinalis, or 

 " Guttlefish" Guttle-bone Loligo vulgaris Edible 

 Cuttlefish Chemical nature of their Colour Nau- 

 tilus -Jlrgonauta Garinaria. 



GASTEEOPODA. 



The Tynan purple Curious properties of the colouring 

 matter of Sea-snails -J/Lurex brandaris (Purpura 

 lapillus Helix fragilis Yandina fragilis (Pur- 

 pura patella -J&urex trunoatus Experiments with 

 Jlmerican Sea-snails Colour furnished by "Whelks 

 Ijuccinum Influence of light upon the production of 

 their colour (Process used by the ancients to dye pur- 

 ple Uric acid in G-asteropoda -Jtfurexide Snails 

 that are reared for food, etc. Helix pomatia Snail 

 gardens H. aspersa H. horticola jlrion rufus 

 Chemical jlnaly sis of Snails Limacine Helicine 

 Uric acid in H. pomatia Turbo littoreus, or (Peri- 

 winkle Haliotis Snails used as money Gyprcea 

 moneta Other species of Cyprcea " Love-shells" 



