6 THE VOYAGE OP H.M.S. CHALLENGER. 



acute, tapering spine. The internodes comprise from seven to eleven zooecia, usually 

 seven or nine, and the branches always arise from the second. Zooecia about half connate, 

 produced above and curved abruptly forwards ; aperture circular, even, border thin. 

 Surface sparsely punctate ; dorsal aspect finely striated, with a row of punctures down 

 each interspace. Branches convex before and behind, and without any intermediate 

 longitudinal space. Joints white or pale brown. Ooecial cells ? Branches '2 to 0*25 mm., 

 zooecia 0"1 mm. wide. 



Habitat— StSition 320, lat. 37° 17' S., long. 53° 52' W., 600 fathoms, green 

 sand. 



Somewhat like Crisia denticulata, but difi"ering in the general habit which is 

 characterised by the very long, straggling, wavy, or flexuose, sparingly forked branches, 

 sterminating in two or three short forks. Many of the ultimate segments exhibit a longer 

 or shorter, acutely tapering, pointed spine, formed of a metamorphosed zooecium. A 

 similar disposition may be occasionally seen in a species of Crisia, to which I have given 

 the name of Crisia sindairensis (Brit. Mus. Cat., pt. iii. p. 6, pi. iv. figs. 7-11), but in 

 this species the spinous process thus formed is much more obtuse, and there are other 

 differences which prevent their being considered the same. 



(6) Crisia acropora, Busk. 



Crista acropora, Bk., Voy. of Eattles., vol. L p. 351; Brit. Mus. Cat., pt. iii. p. 6, pi. v. figs. 3-4; 

 Macgilliv., loe. cit., Dec. iv. p. 38, pi. xxxix. fig. 3. 



Character. — Cells nine to thirteen in each internode; a conical tooth (sometimes 

 bifid) behind the orifice. Zocecia slightly compressed ; surface closely punctured, brilliant, 

 sometimes porcellanous. Branches arising from the second to the fourth zooecium. 

 Ooecial cells large, pyriform, frequently annulated. Branches 0"25 mm., and zooecia about 

 0"06 mm. wide. 



Habitat. — Station 161, off" Port Philip, 33 fathoms, sand. 



[Bass Strait, R.; Williamstown and Queenscliff, Macgilliv.] 



In this species the radical tubes are much curled, always arising from the bottom of 

 the lowest cell in an internode, behind. 



(7) Crisia holdsworthii, Busk (PI. III. fig. 2, ooecium). 



Crisia holdsworthii. Busk, Brit. Mus, Cat, pt. iii. p. 7, pL vi.B fig. 2. 



Character. — Zooecia nine to eleven in each internode, connate throughout, with a 

 short, tubular, cylindrical prolongation projecting directly forwards; walls very delicate, 

 sparsely punctured ; branches arising usually from the third, but in the lower internodes 



