6 E. KIRKPATEICK. 



• 



sieve-like pore-areas ; tlie pore-areas are distributed over the surface up to the 

 neighbourhood of the oscule. 



Canal System. The pores lead into sub-dermal channels whence canals descend 

 into the choanosome. The flagellated chambers are eurypylous. 



Small ova, 60 x 30 /x, with pseudopodic-like processes, occur in the largest 

 specimen. 



A young specimen is pear-shaped with a granular surface, and without a 

 root-tuft. Each " granule " is a sharp-pointed conule, with a protriaene projecting 

 from it. 



The young specimen of Craniella sagitta has a very diff"erent appearance, being 

 quite fluffy on the surface owing to the numerous tufts of protriaenes. 



Specimens were obtained from : (1) West of Balleney Island in 254 fms., Type 

 specimen (XI. 4) ; (2) W.Q., Flagon Point, 10-20 fms. ; (3) W.Q., Hut Point, 25 fms. 



The ' Challenger ' dredged specimens off' Kio de la Plata, 600 fms. 



CiNACHYRA BARBATA. 



(Plate IX., figs. 1-14.) 



1888. Ginachyra larhata Sollas (21. p. 23. Pis. III., XXXIX.). 

 1906. Ginachyra harbata Kirkpatrick (10. p. 662. PL XIV.). 



Twenty-seven specimens of this sponge, varying in diameter from a few 

 millimetres up tq 14 centimetres, were obtained. In addition to these, the collection 

 includes a massive root-tuft no less than 32 cm. across and 12 cm. in thickness, 

 belonging to what must have been a very large specimen, for the concavity into whith 

 the latter fitted occupies nearly the whole area of the upper surface of the root-tuft. 

 The largest specimen obtained by the 'Challenger' — from Kerguelen — was 10 cm. in 

 its longest diameter. 



As in the case of the ' Challenger ' specimens there is a considerable variation in 

 the shape, which is usually spheroidal ; some specimens are spherical, the nucleus of 

 the radiating bundles of the skeleton being exactly central, others again resemble an 

 inverted cone, and very young specimens are oval. 



An interesting feature shown in adult specimens is the division of the sponge into 

 three zones, viz., (1) a basal root-tuft zone; (2) an equatorial zone of porocalyces ; 

 and (3) a polar zone of oscules. 



These zones are clearly perceptible in the fine series of well-preserved Antarctic 

 specimens, but are not so well marked in those obtained by the ' Challenger.' The 

 surface pile of spicules in the porocalycal zone is longer and looser than in the oscular 

 zone, and directed obliquely downwards ; but the pile in the oscular area is shorter, 

 and more vertical and stubble-like. 



The root-tuft. A remarkable feature about the root-tuft is its great size in 

 some specimens, in which it may be much more bulky than the sponge body ; 



