16 E. KIRKPATEICK. 



stauractins and pentactins are peculiar pentactins with very short, closely-spined 

 paratangential rays and a long, smooth proximal ray ; the proximal ray of the 

 ordinary autodermal pentactins is thick and closely spined in its whole length. It 

 is possible that the specimen O.C. 4399 in the British Museum is not specifically 

 identical with the type specimen of S. mitsukurii Ij. in Tokyo. 



Aulorossella includes three species, all new, collected by the ' Discovery ' in the 

 Antarctic Region, viz., Aulorossella pilosa, Aulorossella levis, Aulorossella longstaffi.. 



Aulorossella pilosa. 

 (Plate 11. , fig. 1, and Plate VI. figs. 2-2k.) 



Sponge in form of an oval slightly compressed sack, having an oval orifice with 

 thin unarmed margin, the wall provided with large sharp-pointed conuli mostly 

 with long tufts of diactin and, rarely, anchor-like pentactin pleuralia. Gastral cavity 

 deep, and with a continuous finely pilose surface. "With a dense, massive root-tuft 

 composed of diactins and anchor-like pentactins. 



The intermedia include holoxyhexasters — a form in which each primary ray 

 ends in four or five secondary rays being especially abundant — hemioxyhexasters 

 and, rarely, monoxyhexasters. There are three specimens of this species, all about 

 the same size. The largest is 14 cm. in total height, and 9x6 cm. in diameters 

 of the body about the middle ; the pleuralia extend 3 • 5 cm. from the surface. 

 The body -wall attains a thickness of 2 cm., and the conuli a height of 7 mm. 



The dermal surface shows a fine lace-like network beneath which are seen the 

 openings of the ostia. 



The gastral surface (VI. 2) has a finely pilose appearance when viewed laterally, 

 and feels rough, these characters distinguishing the species from the nearly related 

 Aulorossella levis, which has a smooth gastral surface. The surface is finely reticulate, 

 the meshes being "2 to '3 mm. in diameter and • 2 mm. in depth ; the meshes are 

 formed of strands of hypogastral diactins, bristling with hexactins ; about six meshes 

 stretch over each of the postica. 



Skeleton. The framework is made up of bundles of diactins ; beneath the dermal 

 and gastral surfaces are numerous thick curved isolated diactins roughened at the 

 ends ; medium-sized parenchymal hexactins occur only rarely. 



Spicules. The prlncipalia are diactins varying greatly in length and diameter ; 

 they attenuate very gradually to roughened, blunt-pointed ends. 



The autodermalia (VI. 2b) are pentactins with the rays straight, thickly spined, 

 and diminishing gradually to a thick, blunt end ; the paratangential rays are each 131 

 X 18ju. in diameter, and slightly bent downwards towards the odd proximal ray. 



The hypodermalia are pentactins (VI. 2c) with smooth, slightly curved 

 paratangential rays, each 320 X 40)U,, making an angle of 70° to 80° with the shaft ; a 

 distal knob or swelling may or may not be present ; the odd proximal ray is 2400/i, in 



