S6'2 APPENDIX. 



1. Velella. — The membrane of the body dark 

 blue ; the pretty convex gristly shell is but a very 

 little lighter, the usual transverse line dividing the 

 shell in two, very deeply grooved; the skin surround- 

 ing the sail beneath, dark blue; above, paler; the 

 tentacula, blue at the basis, at the end reddish- 

 yellow. Length of the body, two inches. — At the 

 Cape of Good Hope. 



2. Velella — Membrane of the body, dark blue 

 only at the edge ; gristle shell, pale yellow ; the 

 skin enclosing the sail, colourless: the tentacuhy 

 at the basis, blue ; at the end, reddish yellow. 

 Length of the shell, scarcely an inch and a half. — 

 In the North Pacific Ocean, about the thirtieth 

 degree of latitude. (For the most part, annuals not 

 fully grown.) 



B. The gristly shell extends from the front angle 

 of the left side of the body, to the back angle of the 

 right side. 



3. Velella, — Membrane of the body, dark blue; 

 shell brown ; the skin enclosing the sail, pale blue ; 

 the tentacula, at the basis, light brown ; at the end, 

 dark blue ; body three inches long, but much nar- 

 rower in proportion than the two preceding. — Un- 

 der the equator, in the neighbourhood of Radack. 



4. Velella. — Membrane of the body, dark blue, 

 shell yellow; the skin enclosing the sail, remark- 

 ably green. Length above two inches ; nearly an 

 inch and a half broad. — Li the Northern Pacific 

 Ocean, north of the Sandwich islands. 



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