REPORT ON THE TUNICATA. 1 13 



Cynthia 'pallida, Heller (PL XVII. figs. 17-21). 



Cynthia pallida, Heller, Beitrage zui nahern Kenntnisa der Tunicaten, p. 14, Taf. iii. figa 17, 



18 (Sitzb. d. k. Akad. d. Wiss., Bd. Ixxvii. Abth. 1, 1878)'. 

 Cynthia pallida, Herdman, Prelim. Hep., Proc. Roy. Soc. Edin., 1880-81, p. 60. 



The external appearance of this species has been fully described by Heller, and the 

 Challenger specimens agree well with that description. The branchial sac has eight folds 

 ivpon each side. One specimen has nine. There arc six internal longitudinal liars upon the 

 side of a fold, and only three in the interspace. The transverse vessels are of two sizes 

 placed alternately (PI. XVII. fig. 17, tr. and lr.'). The meshes are square or slight lv 

 elongated transversely; they contain each six or seven stigmata, and are divided l>\ a 

 narrow horizontal membrane (h.'m.'). As noticed by Heller, there are curious elongated 

 and fusiform calcareous spicules in the branchial sac (PI. XVII. fig. 17, sp.) and mantle 

 of this species, and smaller ones are present in the test. When Heller described this 

 peculiarity in 1878, it was, I believe, the first time such a thing had been noticed. Two 

 of the new species of Cynthia discovered by the Challenger expedition {Cynthia 

 complanata and Cynthia papietensis) show similar spicules in the test, mantle, and 

 branchial sac. 



In the present species, the spicules of the branchial sac are chiefly in the wider transverse 

 vessels, and the internal longitudinal bars. They are elongated, slender, and pointed at 

 both ends. In the mantle (PI. XVII. fig. 18, sp.) they are more crowded, and are shorter 

 and stouter. When enlarged sufficiently, it is seen that they are minutely echinated all 

 over (PI. XVII. figs. 19 and 20), and that the pointed spines lie all in one direction, and 

 are arranged in closely placed transverse rows. 



The dorsal lamina is in the form of a series of long tapering languets, united at their 

 bases by a narrow membrane w T hich, like the vessels of the branchial sac, contains elongated 

 fusiform spicules (PL XVII. fig. 21). The tentacles are of two sizes, eighteen larger and 

 eighteen smaller being placed alternately. 



The dorsal tubercle is small, and is usually transversely ovate in shape. In one 

 specimen examined both horns were coiled inwards, while in another one born turned in 

 and the other out, forming spiral coils. 



In the third part of the Preliminary Report, some small specimens from Tahiti were 

 included under this species. 1 have since determined that they are distinct, and they 

 will be described below under the name of Cynthia papietensis. 



Of the specimens of Cynthia pallida in the collection, one is from Simon's Bay, Cape of 

 Good Hope ; depth, 10 to 20 fathoms ; and two are from Kandavu, Fiji Islands. 



Cynthia papietensis, n. sp. (PL XVII. figs. 10-1G). 



External Appearance. — The body is irregularly ovate or elliptical in shape: it is trans- 

 versely elongated, and compressed laterally. The posterior end is wide and rounded ; t he 



