JOURNAL OF MICROSCOPICAL SCIENCE. 



EXPLANATION OF PLATE X. 

 Illustrating Mr. Huxley's paper on Appendicularia. 



Fig. 



1. — Appendicularia flagellum seen from the side to which the caudal 

 appendage is attached, i. e. the dorsal or hiemal side. 



2. — Body of Appendicularia, magnified ; side view. 



3. — Body of Appendicularia, magnified ; dorsal view. 



4. — Caudal appendage ; showing the great nerve, with its ganglionic 

 enlargements. 



A, Body. B, appendage. 



a, oral aperture. 



6, pharynx, giving off its lateral canals. 



c, external opening of these canals. 



d, ciliated circular bands, corresponding with the stigmata of the 



branchial sac in ordinary Ascidians ; but here forming ]iart of 

 the wall of the canal h, c. 



e, anus. 

 /, rectum. 



g, oesophageal narrowing of pharynx. 



/*, right lobe of stomach. 



i, left lobe. 



h, testis. 



I, axis of caudal appendage. 



m, rounded granular masses projecting from the hajmal wall of the 

 pharynx, and of doubtful nature. 



n, Endostyle ; here, as elsewhere in the Ascidians, the optical expres- 

 sion of the thickened bottom of a groove or fold, continuous at 

 its edges with the epipharyngeal bands. 



0, one end of the heart. 



p, ganglion. 



q, ciliated sac. 



r, otolithic sac. 



s, nerve trunk. 



t, ganglionic enlargements upon its caudal portion. 



