THE 



MONTHLY MICROSCOPICAL JOURNAL. 



APEIL 1, 1874. 



I. — Contributions touurds a Knowledge of the Apj^endicidaria. 



By Alfred Sanders, F.L.S., F.E.M.S., Lecturer on Comparative 

 Anatomy at the London Hospital Medical College. 



{Read before the Royal Microscopical Society, March 4, 1874.) 



Plate LVI. 



The interest wliich formerly attached to the Appendicularia, on 

 account of their resemblance to the larvae of the Ascidians, was 

 increased tenfold when Kowalewsky pointed out the relation of the 

 latter to the vertebrata through their mode of development. It 

 was with no little pleasure, therefore, that one fine breezy morning, 

 during the spring-tides of the month of September, I recognized 

 one of these forms in a vessel of sea-water from the harbour of 

 Torquay, which I was examining. They were not very plentiful, 

 perhaps there might have been half-a-dozen or so in each bucket of 

 water. Neither did they stay very long ; shortly after high water 

 no more were to be found, and it was necessary to wait until next 

 day for further specimens ; and at the end of three days they re- 

 turned no more, and the supply was inexorably cut off. 



The animal combined the characters of two distinct species, 



EXPLANATION OP PLATE LVI. 



Fig. 1. — Side view of the long-bodied form of Appendicularia. 

 „ Irt. — Distal termination of the appendage. 

 „ 2. — Dorsal view of the anterior part of same. 

 „ 3. — The same, seen in a position intermediate between the dorsum and the 



side. 

 „ 4. — Side view of the short-bodied form. 

 „ 4rt. — Distal termination of the appendage. 



Letters same in all. 

 A, Anus. M, Mantle. 



A, B, Inhalent aperture of the branchial M, S, Smooth muscular fibre, 

 chamber. M, St, Striated do. do. 



Ap, Appendage. N, Nerve. 



B, C, Branchial chamber. O, Otolithe. 



C, B, Ciliated branchial apertures. 05, O^^sophagus. 

 C, A, Central axis. Ov, Ovary. 



C, K, Ciliated ridge. Py, Pyriform body. 



E, Endostyle. K, Rectum. 



G, Granular body. S, Stigmata. 



I, 1 ; I, 2 ; I, 3 ; Intestine : the greater St, Stomach. 



part seen through the walls of the Ts, Testis. 



stomach. 



VOL. XI. M 



