Nachdruck verboten 

 UeberaetziingareclU vorbthalten. 



On the supposed Vertebration of the Tail in 

 Appendicularia. 



By 

 James ßankiu, B. Sc, 



Assistant in the Department of Zoology and George A. Clark Scholar in Biological 

 Science in the university of Glasgow. 



With Plate 18. 



By the earlier investigators of the Appendiculariœ from Chamisso 

 downwards no mention seems to be made of any apparent segmen- 

 tation in the tails of these animals. This is evidently due to the fact 

 that the interruptions in the muscular layers of the appendage are 

 very rarely, if ever, seen in living specimens. Fol, who treated the 

 animals with various reagents, does not record their appearance 

 although he has most minutely described the phenomena connected 

 with the various genera and species which came under his observation. 



Ray Laxke.ster*) is among the first who have made mention 

 of the muscular interruptions above referred to. He states, as the 

 result of the examination of some specimens of FritiUaria furcata 

 at Naples in 1871 — 72, that "the musculature of the tail is broken 

 up into a series of myomeres, seven in number, one corresponding to 

 each pair of nerves given ofl by the axial nerve-cord". Further in 

 his article "Vertebrata" in the Encyc. Brit. *), dealing with the 

 question of the admission of the Tunicata to the phylum Vertebrata, 

 he says "the Ascidian tadpole, and more clearly the free-swimming 



1) in: Quart Journ. Microsc. Sc, (N. 8.) V. 22, 1882. 



2) in: Encyc. Brit., 9'-^ Edition. 



19* 



