154 "THETIS SCIENTIFIC RESULTS. 



be summarised : — dichotomous biauching approximately at right 

 angles and in one plane ; absence of anastomosis ; the axis of the 

 internodes hard, white, not striated; low, rounded, tubercular 

 polyps arranged in a rather irie<;ular manner, in spirals, and 

 oppoisite ; chief forms of spicules. — (1) lurge cylinders (-28 to -31 

 X 087' mm.), fusiform to sub-clavate, with thick axis, slightly 

 tapering to round-pointed ends, provided with strong tubercles 

 with tendency to arrangement in whorls ; (2) smaller spindles 

 (•21 to -25 X -053 to 071 mm.), more or less curved, with sharp 

 ends and roughened tubercles. 



The colour of the specimens is yellowish-brown. 



Locality. — South Coast of New South Wales. 

 Previously recorded from Port Molle, Queensland, 12-30 

 fathoms ; Port Darwin, 8-12 fathoms ; East Australia, 42 fathoms. 



Genus P A R I S I S, Verrill. 



• PARISIS AUSTRALIS, Wright and Studer. 



(Plate Ixx.) 



Parisis austraUs, Wright and Studer, Chall. Rep., Zool., xxxi., 

 1889, pp. 183-184, pi. xli., fig. 5. 



Stations 13, 34, 44, 47, 48. 



This species was founded on two fragments, much overgrown 

 by an encrusting sponge. In the present collection there are 

 numerous specimens, many of tliem almost entire, so that we are 

 able to amplify the original description. 



The largest colony is 35 cm. high, with a spread of 18 cm. 

 From a slightly encrusting calcareous base arises the cylindrical 

 stem, with an average diameter of 6 mm. which soon begins to 

 give off branches. These arise on the sides, alternately and in 

 one plane. 



Higher up all distinction between main stem and branches is 

 lost. The upper part of the colo^iy consists of a close tangle of 

 equal sized branches, 3-3-5 mm. in diameter, which divide dichto- 

 mously or give off short branches quite irregularly, but invari- 

 ably in one plane. The tendency is for all the branches to bend 

 upwards at the tip, and the axillary angle is 45"-60°. Though 

 the branches often overlap one another, or even entwine slightly, 

 there is never any anastomosis. 



The surface of all the colonies is more or less encrusted with a 

 siliceous sponge, which often entirely obscures the underlying 

 stcuctuie, and produces by its numerous projecting spicules a 

 curious brown, velvety surface. Beneath this is the hard pave- 

 ment-like surface-layer of the Parisis, consisting of cream-white 

 coenenchyma spicules. 



