236 THE VOYAGE OF H.M.S. CHALLENGER. 



The internal longitudinal bars and the papillae are very strong and coarse, and the 

 former are placed pretty close together (PI. XXXIV. fig. 8), so as to bound long narrow 

 meshes, each usually containing two stigmata only. 



The languets along the dorsal line of the sac are very short, and are curved so as to 

 have a hooked shape (PL XXXIV. fig. 9). The tentacles are very few, and are all of one size. 



The dorsal tubercle (PL XXXIV. fig. 1 0) is simple, and is very similar to that of 

 Ciona intestinalis. 



One specimen of this species was dredged off Gomera, Canary Islands, February 10, 

 1873, in 78 fathoms. 



Ciona savignyi, n. sp. (PL XXXV. figs. 1 and 2). 



External Appearance. — The shape is probably oblong and nearly cylindrical, like that 

 of Ciona intestinalis; the posterior end of the body is rounded and broad. The dorsal 

 and ventral edges are nearly straight, tapering somewhat anteriorly. The body is 

 attached by the left side at what would probably be one-third of the way forwards from 

 the posterior end in the fully expanded condition. The apertures are rather close, 

 terminal, and inconspicuous through contraction. 



The surface is smooth, except at the posterior end of the left side and the ventral edge. 

 The colour is whitish grey, hyaline where the test is thin. 



Length of the body, 1*3 cm.; when expanded, probably 2 to 2 "5 cm. ; breadth of the 

 body, 1*2 cm. 



T/ie Test is moderately thick and strong, but is transparent. Vessels are present, but 

 not conspicuous. 



The Mantle is thin, but strong ; and the musculature is well developed. A few strong- 

 longitudinal bands of fibres run down nearly the whole length of the body to the posterior 

 end, and are crossed by closer, but weaker, chiefly transverse, fibres, which are not arranged 

 in broad bands. 



The Branchial Sac is rather strong, and is not plicated. The alternate transverse 

 vessels are wider than the intermediate ones. The internal longitudinal bars are narrow, 

 and bear large paddle-shaped papillae at the angles of the meshes, and no intermediate 

 ones. The meshes are rather larger transversely than longitudinally, and contain each 

 about five rather large stigmata ; each mesh is generally divided transversely by a narrow 

 horizontal membrane connecting the internal longitudinal bars, but not interrupting the 

 stigmata. 



The Endostyle is conspicuous, undulating, and opaque white. 



The Dorsal Lamina is formed by a series of rather large and close-set languets. 



The Tentacles are filiform, and are rather long and numerous. 



The Viscera extend posteriorly for a short distance beyond the branchial sac, and 

 form the posterior end of the body. 



