ASCIDIANS OF THE PHILIPPINES VAN NAME. 115 



and ends, first becoming very slender and merely crossing without 

 terminating the stigmata ; the supporting papillae that bear it be- 

 come correspondingly reduced, and finally disappear as the vessel 

 terminates. 



Digestive tract on right side of body. Stomach rather short and 

 rounded, with conspicuous longitudinal folds in its walls. Intestine 

 having the peculiar course characteristic of the family, passing ven- 

 tral instead of dorsal to the stomach. Margin of anus with small 

 inconspicuous lobes.. 



Reproductive organs present on the right side of the body only. 

 The ovary is a many-branched organ lying within the intestinal 

 loop, its branches spreading out to a slight extent on the surface 

 of the loop next to the mantle. Testis not developed in specimens 

 examined. In this genus it is of ramified form, spreading over the 

 surface of the intestinal loop. 



The localities of the specimens in the collection are : 



No. 77. Station D5250 (off Linao Point, Gulf of Davao, May IS, 1908, 23 

 fathoms, coral sand) (Cat. No. 5964, U.S.N.M.). 



No. 69. Station D5139 (near Jolo Light, Feb. 14, 1008. 20 fathoms, coral 

 sand). Large individual somewhat incrusted with foreign ma- 

 terial (Cat. No. 5963, U.S.N.M.). 



No. 93. Station D5145 (near Jolo Light, Feb. 14, 190S, 22 fathoms, sand 

 and shells (Cat. No. 5903. U.S.N.M.). 



No. 195. Station D5137 (near Jolo Light, Feb. 14, 190S, 20 fathoms, sand 

 and shells), (Cat. No. 5993. U.S.N.M.). 



No. 8S. Station D5147 (Sulu Archipelago, near Siasi, Feb. 1G, 1008. 21 

 fathoms, coral sand and shells). Very small and immature 

 individual (Cat. No. 5930, U.S.N.M.). 



This species, originally described from Chinese waters (Stimpson, 

 1885), appears to be widely distributed in the warmer parts of the 

 western Pacific and in the Malay Region, and probably ranges &till 

 more widely, for Rk. ceylonicum Herdman (1906) from Ceylon, and 

 Rh. huxleyi MacDonald (1862) from Australia, 1 do not appear to be 

 separated from it by any characters of importance. It was ob- 

 tained at many stations in the Malay Region by the Siboga Expedi- 

 tion, 118 meters being the greatest depth. The reader is referred to 

 the article by Hartmeyer (1901) for a discussion of the species of 

 this genus up to that date; also to Herdman, 1906. pages 302 and 

 303. The Avriter follows in the present paper all recent authors in 

 employing the name papillosum for this species, but does not lose 

 sight of the fact that Stimpson's Rh. pellueidum, also from China,, 

 which as Hartmeyer (1901, p. 161) suggests, is very probably 

 identical with papillosum, is described as species No. 19 of Stimp- 

 son's article (1855) while papillosum is described as No. 20 of the 

 same article. In case the identity of the two forms can be proved 



1 See Willey, 1902, p. 711, fig. 11. 



