96 THE AUSTRALIAN MUSEUM. 



to those in the alimentary canal of an Ascidia, but the first bend of the 

 intestine is at a more acute angle than in the Simple Ascidian, and the 

 second at a more obtuse angle. The dorsal end of the stomach is thrown 

 into thick folds, and appears to be glandular. The remainder has smaller 

 longitudinal folds. The usual system of fine tubules (fig. 6), ending in 

 ampullae, is found ramifying over the intestine, and opening by a common 

 duct into the stomach. 



The reproductive organs consist of rounded polycarps (fig. 7) imbedded 

 in the mantle, and projecting slightly into the peribranchial cavity. 



There are three colonies of this species from Port Jackson. The 

 largest is about 15 cm. in length. All the four known species of 

 Cliorizocormus resemble one another closely in external appearance, 

 although they differ markedly in internal structure. The present species 

 (PL Pst. I., fig. 1) is rather like the "Challenger" Ch. reticulata in 

 form, but is darker in colour. The common test in this species is highly 

 vascular, and the terminal knobs are very numerous (fig. 2). The 

 branchial sac has large, distinct meshes (fig. 3), and the stigmata are 

 regularly arranged. 



The Ascidiozooids form dark patches in the light-grey transparent 

 test, which is dotted all over with the opaque terminal knobs of the 

 vessels. 



Chorizocormus subfuscus, Herdm., ::: PI. Pst. I., figs. 811. 



External appearance. The colony is formed of a number of elongated 

 and rounded masses, containing Ascidiozooids, and united by thinner 

 portions of test, so as to form an irregular network, attached to several 

 colonies of Polyzoa, of the genera Betepora and Amathia (fig. 8). The 

 test is of a dull grey colour, while the bodies of the Ascidiozooids give a 

 purplish brown colour. 



The test contains many vessels, with the usual terminal knobs, filled 

 with dark blood corpuscles (fig. 9). There are no bladder cells ; the test 

 cells are few and very small. 



The Ascidiozooids measure about 3 mm. by 2 - 5 mm. No separate 

 abdomen is present. 



The mantle is delicate, with greenish brown pigment cells. The 

 larger muscle fibres run longitudinally ; there are only a very few fine 

 transverse ones. 



The branchial sac has internal longitudinal bars. There are at least 



* "Revision," p. 636. 



