REPORT ON THE TUNICATA. 119 



The Test is rather stiff and thick — thicker than in tin- three last described species. 

 It is quite opaque. The outer surface is very rough, the papilla? heing larger than and 

 nearly as numerous as in Cuh-oltis j >,■)•/< it us. Tiny arc dome-shaped, or of a short conical 

 form. 



The test between the papillse has a yellowish-grey tint, in some places hyaline, while, 

 the papillse are of an opaque yellow, thus adding greatly to the general yellow effect and 

 opacity of the body. There is no foreign matter adhering to the surface. 



The surface of the peduncle is slightly uneven from the same cause as in the last 

 species. In this case, however, the trabecular are fewer in number, consequently the meshes 

 are much larger and are more irregular (PI. X. fig. 10). The dark brown trabecular are 

 distinctly visible to the eye, and the matrix between them is of a bluish-grey colour, and 

 semi-transparent. 



The Mantle is thin, but the musculature is stronger than in the last three species. 

 The muscle bands are strong, and in some parts are distant, while in others they are 

 closely placed, forming a strong, but generally irregular, network. 



Tlie Branchial Sac is delicate, and has several slight folds on each side. They 

 aii' similar to those in Culeolus perlatus, each having four or five internal longitudinal 

 bars, which, however, are rather more closely placed (PI. X. fig. 11, br.f.). 



The transverse vessels are narrow and are all of the same size. The internal longitudinal 

 bars are wider, and, as in the last species, form the strongest part of the network. 



The meshes are square and are moderately large. Here and there secondary sbghter 

 transverse vessels and fine longitudinal vessels (PI. X. fig. 11, l.t.) may be seen crossing 

 the meshes, but they are rare. 



Calcareous spicules are present in the vessels as usual, chiefly in the internal 

 longitudinal bars. They are large and branched like those in the last species, and are 

 numerous. 



The Endostyle. — This organ, as usual, may be divided into an outer clear edge on 

 each side, and a central, more opaque area (PI. XIII. fig. 3). The edge (u\e.) on each 

 side occupies about one-fourth of the entire width of the endostyle, and is transparent 

 and covered by a layer of tesselated epithelium distinctly nucleated. This edge is 

 bounded internally by a rather broad opaque yellowish-brown band (l.b.b.), which is 

 separated by a narrow clear area from a slightly broader but similar band (<■./*.".), divided 

 from its fellow of the opposite side by a narrow clear stripe. Consequently the central 

 area is traversed by four broad bands running longitudinallv, and separated by narrow 

 dear stripes. Calcareous spicules are plentiful, and are scattered over the entire 

 breadth of the organ, being present, however, in rather greater quantity in the central 

 area than in the clear edges. They are large and considerably branched (PI. XIII. 

 fig. 3, sp.). 



The Dorsal Lamina. — As usual, this is represented by a scries of triangular languets. 

 They are rather small and pointed. 



