XLI 



FURTHER OBSERVATIONS ON THE STRUCTURE OF 

 APPENDICULARIA FLABELLUM (Chamisso). 



Quart. Journ. Microsc. Sci., vol. iv., 1856,//. 181-191. 



In a paper read before the Royal Society in 185 1, I gave an 

 account of a very singular animal which had been frequently observed 

 and described under various names, as Appendicularia (Chamisso), 

 Oikopleura (Mertens), Fritillaria (Quoy and Gaimard), Vexillaria (J. 

 Miiller), and Eurycerciis (Busch), but whose precise place in the animal 

 kingdom was still a matter of doubt. The essential points in that 

 account will be found in the following extracts : — ^ 



* * * ^- e^ 



" The animal has an ovoid or flask-like body one-sixth to one- 

 fourth of an inch in length, to which is attached a long curved lanceo- 

 late appendage or tail, by whose powerful vibratory motions it is- 

 rapidly propelled through the water." 



" The smaller extremity of the animal is perforated by a wide 

 aperture {d) which leads into a chamber, which occupies the greater 

 part of the body, and at the bottom of this chamber is the mouth. 

 The chamber answers to the respiratory cavity of the Tunicata, and 

 is lined by an inner tunic distinct from the outer ; the space between 

 these, as in the Salpce, being occupied by the sinus system. 



" On the side to which the caudal appendage is attached, an 

 endostyle {c), altogether similar to that of the SalpcE, lies between the 

 inner and outer tunics ; and opposite to this, or on the ventral side 

 close to the respiratory aperture, there is a nervous ganglion, to which 

 is attached a very distinct spherical auditory sac, containing a single^ 

 also spherical, otolithe. The sac is about i -200th of an inch in 

 diameter. The otolithe about i -Sooth, figs, i, 2, 4 «. 



^ Nova Acta Acad. Curiosorum, t. xi. pars secimda, pp. 313 and 314. 



G G- 



