ASCIDIANS OF THE PHILIPPINES VAN NAME. 123 



Owing to the peculiar form of the body the anterior part of the 

 branchial sac is much narrower than the posterior part. Four rows 

 of long narrow stigmata are present ; about 35 stigmata on each side 

 in the anterior row, the number increasing gradually to nearly 50 in 

 the posterior row. The three transverse vessels on each side; each 

 bear about 15 or 16 papillae distributed fairly evenly along their 

 length. These support slender longitudinal vessels, which (except 

 those borne on papillae near the endostyle and median dorsal vessel) 

 are mostly complete between the first and third transverse vessels but 

 elsewhere are represented only by anteriorly or posteriorly extend- 

 ing branches of the papillae. Because of the increase in the number 

 of stigmata in the posterior rows the internal longitudinal vessels are 

 separated by only about two stigmata in the anterior part and by 

 three or more in the posterior part of the sac. 



Intestinal loop rather long dorso-ventrally and narrow in an an- 

 teroposterior direction. It is situated in the left posterior dorsal 

 part of the body. The esophagus, which is much curved, begins at 

 the posterior dorsal part of the sac; the stomach is small, oval, and 

 smooth-walled; the intestine has a very marked valvelike constric- 

 tion some distance beyond the stomach and is of larger diameter 

 beyond the valve, tapering gradually from this point to the anus, 

 which has a lobed margin. 



Reproductive organs small and poorly developed in most of the 

 individuals. In some a small number of pear-shaped testes entirely 

 distinct from each other and each borne on a slender duct can readily 

 be distinguished. They lie in the intestinal loop. Their ducts con- 

 verge in a radial manner to form a stout common sperm duct which 

 accompanies the terminal part of the intestine. In some zooids the 

 ovary is visible as a group of small eggs lying beside the commence- 

 ment of the common sperm duct. 



The only specimen (No. 43) (Cat. No. 5926, U.S.N.M.) is from 

 station D5597 (near Zamboanga Light, Mindadao, Oct. 12, 1909, 9 

 fathoms). MacDonald's type was from Australia. 



Family CIONIDAE Lahille, 1887. 



As restricted by Hartmeyer, this family has consisted only of the 

 well-known and nearly cosmopolitan genus C'iona, which, though 

 found in the Malay Archipelago, has not yet been collected in the 

 Philippines. The family is separated from the Phallusiidae chiefly 

 by having the continuous dorsal lamina replaced by separate lan- 

 guets, but is also characterized by its elongate body, and the power- 

 ful longitudinal muscle bands in the mantle, and by the position and 

 course of the intestine, which lies partly behind and partly beside 

 the branchial sac. 



