410 W. AYRTON ON ZOOTHAMNIUM GENICULATUM. 



years, but have never been able to find it elsewhere. Should any 

 member of our Club discover it in any other locality, I shall be 

 pleased to be informed of it. 



Explanation of Plate 21. 

 Zoothamniujn geniculatuvi, n. sp.* 



Fig. 1. Adult colony-stock, x 15. 



„ 2. Enlarged frond, x 30. 



,, 3. Group of four zooids, x 200. 



,, 4. Colony in act of contraction, x 15. 



,, 5. Apex of pedicle showing branching, x 200. 



,, 6. Reproductive zooid, x 50. 



„ 7. The knee in contraction, x 30. 



„ 8. Muscular fibre and branching of frond, x 200. 



* By an oversight, the name on the Plate has been printed Z. geniculata. 



Journ. Quekett Microscopical Club, Ser. 2, Vol. VIII. , No. 51', April lOOS. 



