104 THE AUSTBALIAN MUSEUM. 



Test, numerous branching vessels (fig. 12), with rather small terminal 

 knobs, which are few and light-coloured. Small test cells, no pigment. 



Ascidiozooids about l - 5 to 2 mm. long. The branchial apertures show 

 as white dots on the surface of the colony. 



Mantle very thin. Muscle fibres almost hidden in masses of dark 

 purple pigment cells (fig. 11). 



Branchial sac very long and narrow. There are at least 11 rows of 

 stigmata, and about 12 stigmata in each row. There are 3 internal 

 horizontal bars on each side, and from 2 to 4 stigmata in a mesh. The 

 stigmata are short and regularly placed. 



Dorsal lamina a narrow membrane (fig. 10). 



Tentacles 16 ; 4 large, 4 about half the length of the last, and 8 very 

 small ones regularly alternating (fig. 10). 



Dorsal tubercle a small circular opening placed just outside the peri- 

 pharyngeal band. 



Alimentary canal. The stomach differs from that of our former 

 Botryllidae in being quite globular, and in having two caeca, a small 

 anterior one, which the duct from the intestinal gland enters, and a 

 longer vermiform posterior caecum, which lies just to the left of the 

 pylorus (fig. 13, ccc.}. The usual intestinal gland is present. The 

 stomach has well-marked folds running from intestine to oesophagus. 

 The rectum widens out so as to have an everted rim at the anus. 



No gonads were found, but young buds were very abundant in this 

 colony. 



Locality. Port Jackson, with Chorizocormus subfuscus. 



Sarcobotrylloides purpureum, Herdm., :;: Pl. Bot. Ill, figs. 6 10. 



Colony massive, irregularly lobed, from pink to purple in tint. Sur- 

 face smooth. No terminal bulbs of vessels visible, nor cloacal apertures. 

 Length 7 cm., breadth 5 cm., thickness 5 mm. 



Systems irregular, chiefly in branching lines (figs. 8 and 10). 



Test with no bladder nor pigment cells. Vessels numerous, with 

 many small ovate terminal knobs, seen in sections (fig. 9). Test easily 

 tears, and Ascidiozooids fall out. 



Ascidiozooids about 5 mm. long and 1 mm. broad at most, with long 

 axis parallel to surface. Branchial apertures show as white dots on the 

 surface of the colony. 



Mantle thin, muscle fibres slight and distant, running longitudinally. 

 A few purple pigment masses. 



* See "Revision," p. 009. 



