ASCIDIANS OF THE PHILIPPINES VAN NAME. 



157 



Zooids over 2 mm. long when fully expanded, but in the preserved 

 specimens generally less. Branchial siphon usually quite long, with 

 six more or less evident lobes. Atrial orifice round, on a short tube 

 or siphon arising from the posterior dorsal part of the thorax, and 

 uusally directed dorsally or dorsally and posteriorly. Muscular or 

 vascular processes extending out into the test were not demonstrated. 



Mantle musculature rather delicate; a moderate number of slen- 

 der longitudinal bands are present on the thorax. 



Four large tentacles in addition to two orders of smaller ones, 

 probably about 16 in all, are present. 



Dorsal languets arising from the transverse vessels of the left side, 

 the width of two or three stigmata to the left of the median dorsal 

 vessel. 



Four rows of stigmata; 15 in the two anterior 

 rows, 14 in the third, and 12 or 13 in the posterior 

 row on each side. 



No peculiarities no- 

 ticed in the digestive 

 or female reproduc- 

 tive organs. Male re- 

 productive organs 

 were found in all ex- 

 cept one of the col- 

 onies. There are from figs. 107, ios.— polysyncraton dubium- sluiter. 



9 to 12 separate pear- Spicules showing variations in form, x 500. 

 . i ; . zooid. x 21. 



shaped testes com- 

 municating with the origin of the common sperm duct or vas 

 deferens by very short connecting ducts. In the specimens from sta- 

 tions D5159, D5555, and D5139 the testes have a regular radial ar- 

 rangement about the origin of the common sperm duct as a center, 

 the duct making at least four or five spiral turns about the entire 

 group of testes. In the specimen from station D5145 and D5174 

 the testes were evidently in an actively functional state and more or 

 less distended and enlarged, so that they are crowded out of their 

 radial arrangement and form a compact more or lass hemispherical 

 group, about which the sperm duct (also much distended with sper- 

 matozoa) makes only about two irregular turns. As it is evident 

 that such a displacement of the testes and partial straightening of 

 the sperm duct would be the natural result of dilation of these 

 organs, the writer can not consider this peculiarity important in 

 classification. 



The above description shows that the writer has assigned to this 

 species specimens differing among themselves a good deal in some of 

 the minor characters. Possibly he has gone too far in this, and should 

 have recognized more than one species, but the limited material 



10o 



107, 

 108. 



