ASCIDIANS OF THE PHILIPPINES VAN NAME. 



93 



sions and elevations. It is not much incrusted with foreign material, 

 except on the pedicel. Dimensions of the two specimens : 



Station Station 



D5174. D5144. 



mm. mm. 



Total length 114 100 



Length of pedicel 44 18 



Dorso-ventral diameter 33 42 



Lateral diameter (average) 16 19 



Distance apart of apertures 24 38 



Mantle thick and opaque owing to the great development of the 

 muscular layers, which form thick sheets. Mantle and internal tis- 

 sues and organs light colored. 



Large tentacles about 16, probably representing two orders ; a few 

 small ones irregularly distributed in 

 the intervals. 



Dorsal tubercle large, longitudi- 

 nally elongate, with a C-shaped aper- 

 ture; open interval to the left, horns 

 inrolled. 



Dorsal lamina rather narrow, but 

 wider posteriorly, plain edged. 



Branchial sac with four well-de- 

 veloped folds on each side. They 

 rise abruptly and are separated by 

 wide intervals. The larger vessels 

 are very stout and muscular. Trans- 

 verse vessels of about five orders, the 

 smallest crossing the stigmata. Internal longitudinal vessels very 

 numerous, separated on the intervals between folds by not more than 

 five to seven stigmata on most parts of the sac and very closely 

 crowded on the upper part of the folds. The following is an ap- 

 proximation to their distribution: 



Right side: dorsal 6 (42) 9 (33) 9 (37) 9 (28) 6 ventral. 

 Left side: dorsal 8 (40) 10 (30) 9 (35) 8 (22) 8 ventral. 



Esophagus short, stomach rather short oval, its walls not much 

 plicated externally ; no pyloric caecum. Intestine large but forming 

 a rather narrow loop. No abrupt bend at the beginning of the 

 rectum, which is rather short. Margin of anus with many minute 

 lobes. 



Gonads small and numerous, irregularly distributed on both sides 

 of the body, but so buried in the tissues of the body wall as to be 

 difficult to distinguish. They are elongate or phial-shaped, often 

 irregularly curved, and sometimes forked or branched. The numer- 



flg. 46. pandocia cibcumarat4 



(Sluiteu). Left and right sides 

 OP BODY. X .75. 



