20 R. KIRKPATRICK. 



(XV. 10) with a small spherical head 20 /* in diameter, with a slender neck, and a thick 

 fusiform shaft, blade-like in optical section, and with tornote end ; a few of these 

 spicules are scattered in the choanosome between the radiating fibres. A second kind 

 (XV. 12) 220 x 20 /j. is straight, with a short, thick neck and cylindrical shaft with blunt 

 point. A third kind (XV. 11) 220 X 7 /u, is slender, slightly curved, and sharp-pointed. 



The new variety differs from the typical form in having stouter cortical and 

 choanosomal spicules. This is at once obvious on looking at the vertical sections of the 

 two forms, the cortical spicules especially being much thicker and denser in the new 

 variety. Again, the poral areas on the surface of the type are small and circular 

 (XV. 14), whereas those of the new variety are stellate (XV. 13). 



The specimens were dredged near Winter Quarters, at No. 10 hole, 130 fms. 



The typical form was obtained from between Kerguelen and Heard Island from 

 150 fms. (Voy. 'Challenger'). 



SUBERITES CAMINATUS var. papillatus. 

 (Plate XV., fig. 16, and Plate XVI., figs. 11-14.) 

 Suberites caminatus Ridley and Dendy (15. p. 198). 



There are two specimens, each firmly attached to a piece of rock ; one has two 

 oscular chimneys, the other only one. The body of the larger specimen is 2 5 cm. in 

 diameter and 1 5 cm. in height, the oscules being 7 mm. in height. 



The upper half or more of the surface is covered with small flattened papillae, each 

 about 1 to 1 25 mm. in diameter, and about '7 mm. high. These structures carry the 

 pores in stellate grooves (XV. 16). At the base of the sponge is a chitinous lamella 

 with tangential tyles scattered irregularly and intercrossing. At the base of the larger 

 specimen the basal lamella is produced into a fringe of little processes formed of 

 flattened bundles of tyles, the distal ends of which have become rounded. The skeleton 

 is formed of radiating choanosomal fibres and of a dense cortical layer of dressed 

 tyles. 



Spicules. Straight fusiform tyles (XVI. 14), 1530 x 20 /u, with small oval head 

 15 x 10 fji. Cortical tyles mostly of two kinds ; one (XVI. 12) with small 

 spherical head, with relatively slender neck and thick cylindrical shaft, blade-like 

 in optical section, with tornote pointed end ; the other (XVI. 13) shorter and 

 stouter and with thicker neck. A fourth kind of spicule, rather rare (not figured), is a 

 sub-tylote, 1,530 x 20 /j. long, with a very slender curved distal end projecting beyond 

 the surface, resembling the distal end of the heteroxea of Stylocordyla. 



The chief variation from the type lies in the poral papillae. In the typical form 

 the pores are in stellate grooves. The papillae of the new variety called to mind the 

 same structures in Trichostemma irregularis R. & D. On examination, the papillae in 

 this species also proved to be poral, with the pores in radiating grooves. 



The two specimens were dredged from a depth of 254 fms., due west of Balleney 



