1855.] 387 



about ten perforations, the middle ones largest. The hamulae are a little larger 

 than the plates, pickaxe-shaped, with the extremity of the handle also provided 

 with a double hook, though of very small size. Tentacula twelve, digitate 

 nearly to their bases ; digitations short, about fourteen in number to each ten- 

 tacle. Length 2 inches. Found under stones, near low-water mark. 

 Hab. Australia, at Fort Jackson. 



TUNICATA. 



7. Cynthia angularis. Small, elongated, with a small base, and seven or 

 eight longitudinal ridges ; test coriaceous, nearly smooth between the ridges, 

 of a pale yellowish color ; apertures square, at the extremities of short tubes 

 which are placed close together at the extremity of the body; each tube with 

 four longitudinal reddish bands corresponding to the angles. Length, 1 inch : 

 breadth, 0.3 inch. On sea- weeds in the circumlittoral zone. 



Hab. Cape of Good Hope, at Simon's Bay. 



8. Cynthia l.evissima. Egg-shaped ; test very thick, of a pale orange 

 color, very smooth and glossy ; apertures small, red. Branchial sac with about 

 20 folds, and with twenty elongated, fimbriated tentacles at its apertures. Some 

 of these tentacles, as is usually the case in this genus, are much smaller than 

 the others. Length 1 inch. Found under stones in the lower part of ihe litto- 

 ral zone. 



Hab. Australia, at Port Jackson. 



9. Cynthia sabulosa. Rounded, laterally compressed, usually attached by 

 one or more short stalks. Test strong and hard, but not very thick ; surface 

 covered with sandy particles, which adhere so strongly as to form part of its 

 substance. Apertures on slight prominences, the branchial largest and dotted 

 with black. Branchial folds eight in number, narrower than their interspaces. 

 Branchial tentacles simple, filamentary, long and very numerous. Diameter 1 

 inch. Found in the circumlittoral zone, on muddy bottoms. 



Hab. Australia, at Port Jackson. 



10. Cynthia dumosa. Globular, of a yellowish-brown color ; surface villous, 

 and provided with numerous stout, sub-conical processes of the test, which have 

 short irregular branches. Apertures cross-shaped when contracted ; the bran- 

 chial more than twice the size of the anal. Branchial sac with twelve very 

 large folds, which are much broader than their interspaces. Tentacula also 

 twelve in number, including four or five small ones ; biserrate, folded longitudi- 

 nally, and curved so as to present their pinnae toward the branchial cavity. Di- 

 ameter 1 inch. Found in the circumlittoral zone, on muddy bottoms. 



Hxb. Australia, at Port Jackson. 



11. Molgula inconspicua. Small, free, bullet-shaped; test thin, brittle, with 

 a thin but solid coating of sand; apertures clear, transparent white; the 

 branchial six- rayed; the anal with four well-marked lobes. Branchial sac with 

 eight fold3 equalling their interspaces in width. Diameter, half an inch. 

 Found in the circumlittoral zone, on sandy bottoms. 



Hab. Australia, at Port Jackson. 



12. Ascidia SYDNEiENSis. Gregarious, several specimens growing together in 

 one mass. Test irregular in shape, thin, often translucent, of a pale purplish 

 color. Apertures on long tubes, which are marked with longitudinal ridges 

 corresponding in number with the rays of the apertures ; the branchial having 

 seven, the anal six rays. Branchial sac finely reticulated, the transverse threads 

 much less prominent than the longitudinal ones. Tentacula simple, thread-like, 

 about one hundred in number, curved and projecting into the cavity so as to 

 form a dome-like filter for the water as it enters the branchial sac. LeDgtb l\ 

 inches. Found near low-water mark, among rocks. 



Hab. Australia, at Port Jackson. 



