ASCIDIANS OF THE PHILIPPINES VAN NAME. 159 



tentacles (probably 16 in all) could be distinguished as in P. dubium, 

 and the number and arrangement of the stigmata is evidently the 

 same or nearly the same as in that species. An atrial siphon could 

 not be demonstrated, but, on the other hand, there was no evidence 

 against its presence. There are a number of separate testes which, 

 though of fair size, are so poorly preserved and in such a soft con- 

 dition that their exact number could not be determined. The vas 

 deferens makes only a few turns about the compact group or mass 

 which they form. 



Genus LEPTOCLINUM Milne-Edwards, 1842. 



[—Diplosoma Authors.] 

 LEPTOCLINUM MACDONALDI (Herdman). 



18S6. Diplosoma macdonaldi Hekdman, Rep. Voy. Challenger, vol. 14, Tuni- 



cata, pt. 2, p. 315. 

 1S91. Diplosoma macdonaldi Hekdman, Jouru. Liun. Soc. London, Zool., 



vol. 23, p. 633. 

 1898. Diplosoma macdonaldi Gottschaldt, Abh. Senckenb. Ges., vol. 24, 



p. 657. 

 1902. Diplosoma macdonaldi Van Name, Trans. Connecticut Acad. Sci., vol. 



11, p. 368, pi. 53, fig. 60 ; pi. 60, fig. 124. 

 1909. Leptoclinum macdonaldi Haetmeyek, Bronn's Tier-reich, vol. 3, 



suppl. p. 1455. 



The only satisfactory specimens in the collection are two small 

 colonies from station D5145, each about 10 mm. in greatest diameter 

 and of a thickness of 2 to 3 mm. Each of them grew upon the cara- 

 pace of a small living crab, arching over it so as to cover all but the 

 lower parts and the appendages of the crustacean. Apparently the 

 ascidians did not interfere with the life of the crabs, and though they 

 must have inconvenienced them in locomotion, they doubtless afforded 

 considerable protection and concealment. In addition to these speci- 

 mens several very minute colonies (containing, hoAvever, adult 

 zooids), certainly of this genus and presumably of this species, were 

 found growing upon and among Didemnum colonies from station 

 D5148. 



Test nearly colorless and more or less transparent. It is fairly 

 firm in consistency and does not contain very extensive common 

 cloacal cavities or ducts. 



Zooids 1.5 mm. long or less when moderately expanded; the in- 

 testinal loop, as well as the abdomen as a whole, are almost always, 

 if not always, strongly bent to one side, so that an exact estimate of 

 the length is difficult. Body only moderately constricted between 

 the thorax and abdomen. Branchial aperture 6-lobed; atrial aper- 

 ture neither produced into a tube nor provided with a languet. 



Tentacles of three sizes, quite regularly arranged. 



