ASCLDIANS OF THE PHILIPPINES VAN NAME. 



141 



When exception.nl ly well preserved and considerably expanded, 

 the zooids may be 4 to 5 mm. long, but in some specimens they are so 

 contracted as to hardly average half the above length. Branchial 

 apertures usually not conspicuously lobed. Atrial aperture very 

 variable in size and form in different zcoids; sometimes it is merely a 

 large opening whose edges are neither lobed nor produced ; in other 

 cases it is smaller and situated at the end of a tubular siphon; in 

 others again the anterior edge is produced into a languet of more 

 or less conspicuous size and length (fig. 93). 



Mantle musculature delicate, composed mainly of slender trans- 

 verse and oblique bands, and circular bands surrounding the aper- 

 tures. 



Tentacles 8 in number; of two sizes, placed alternately. 



Dorsal languets arising from the transverse vessels of the left side 

 at some distance from the median dorsal vessel. 



Stigmata in 4 rows, about 25 in a 

 row on each side. A narrow interme- 

 diate transverse vessel crosses without 

 interrupting the stigmata of each row 

 midway between the larger vessels. 

 The two or three stigmata of each row 

 nearest the endostyle become succes- 

 sively shorter as that organ is ap- 

 proached. 



Stomach rather elongate oval, ta- 

 pering toward the pyloric end. In 

 most colonies it is smooth-walled, but 

 in some colonies more or less distinct 

 longitudinal ridges on the inner sur- 

 face can be detected. 



Intestinal loop generally not twist- 

 ed, and the reproductive organs in 

 consequence lie in the right side of the abdomen. The male organs 

 consist of a group of about a dozen small pyriform or rounded testes 

 arranged in a circle or hemispherical group, the stout thick-walled 

 common sperm duct accompanying the ascending part of the in- 

 testine and rectum. The ovary is a small sac containing a few eggs, 

 lying beside, or more or less surrounded by, the group of testes; 

 the oviduct accompanies the sperm duct and ascending branch of the 

 intestine. No brood pouches were found, though some large larvae 

 were present in the test in one of the colonies. Probably brood 

 pouches are formed in the usual manner, and the larvae observed 

 had made their escape by the rupture or degeneration of the wall of 

 the pouch. 



Fig. 93. — Holozoa 

 man). Zooid. X 



LINE OP THORAX 

 ZOOIDS SHOWING 



VALLII (HERD- 



20. ALSO OUT- 



OF TWO OTHER 



VARIATION IN 



FORM OF ATRIAL ORIFICE. 



