APPENDIX. 



NUMBER I. 



Referred to from the end of Part I. 



[A SYNOPSIS] 

 Of AQUATIC INSECTS covering themselves with cases. 



'Immoveable, being af- 

 fixed to stones ; and 

 have a body either 



Round, with little threads on 



the sides, or 

 Flat) ?nd more compressed, 



without little threads. 



Water insects Or mo'veable t 

 that cover j 

 themselves < 

 with cases, 

 have a case 

 either 



portable and migratory, called "phry- 

 " a cad-case" which is furnished 

 with little threads, as well on the back as the sides, by 

 means whereof they adhere firmly to their cases, ex- 

 cepting only their head and feet : with three small 

 protuberances projecting beyond the feet, which they 

 can erect or put forth at pleasure, to hinder their cases 

 from pressing down on their heads as they creep, and 

 troubling them. 



C v i, , ("The greater being two inches 



Straws ag- I Parallel, \ , * . 



those ei- 

 ther 



' (^ called straw ivorms. 

 Or transverse and shorter, with sometimes 

 small stones and shells intermixed. 



a horn : for the cases of these 

 are crooked, and one extremity 

 is larger, the other less. Of these 



I have known four different species, viz. the black, the greater 

 and less ; and the ash-colour, the greater aad lew. 

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