PLATE IV. 



Fis. 



1 and" 2. Ascidia rnl/u-inida Hanc. (p. 83) 1. Test : three- 

 fifths natural size. 2. Mantle : four-fifths natural 

 size. The projecting tubes on the left are blood- 

 channels communicating with the test. The nerve- 

 ganglion is seen about midway between the two 

 apertures, and on the opposite side is the endostyle. 

 In the centre are the ovary, oviduct, and intestine, 

 seen through the transparent mantle. 



3 and 4. Ascidia Normani A. & H. (p. 132) 3. Test: one 

 and a half times natural size. 4. Mantle : natural 

 size. 



