HYALONEMA (HYALONEMA) GRANDANCORA. 235 



Hyalonema (Hyalonema) grandancora, sp. nov. 

 Plate 7S, tigs. 16-45; Plate 79, figs. 1-26. 



One specimen of this species was trawled in the Southeastern Tropical Pacific 

 at Station 4701 on 26 December, 1904; 19° 11.5' S., 102° 24' W.; depth 4142 m. 

 (2265 f.); the bottom was composed of dark brown chocolate clay; the bot- 

 tom-temperature was 35.3°. It possesses very large macramphidiscs with 

 broad anchors, and to these the specific name I'efers. 



Shape and size (Plate 79, fig. 12). The body of the sponge is upright, 

 sUghtly compressed laterally, somewhat phcated, and rounded l:)elow. It 

 is 35 mm. high, 42 imn. broad, and 20 mm. thick. The upper part is much 

 injured. In the fresh state its apical face was probably concave, with a broad 

 gastral cone arising from its middle-part. Around the gastral cone, which is 

 still present, wide canals, separated by radial lamellae, extend downwards into 

 the interior. An eccentrically situated stalk, 1.4 mm. thick at its point of 

 origin, arises from the lower rounded end of the body. This stalk is broken off 

 below. The upper part, which is still present, is 160 mm. long, and slightly 

 curved in an irregular manner. 



To the upper half of the stalk a colony of eleven polyps (Palythoa sp.) 

 is attached. The polyps of this colony are strongly contracted and about 

 2 mm. high. They have an oval transverse section 4 mm. long and 3 broad, 

 elongated in the direction of the stalk of the Hyalonema. Their stomatodeum 

 is also oval in section and measures 1 by 1.5 mm. The individual polyps are 

 8-15 mm. apart (measured from centre to centre) and distributed all round 

 the stalk in an irregularly spiral manner. The coenenchym forms a thin bark 

 on the stalk of the Hyalonema. From this the individual polyps arise. 



The colour of the sponge-body and of the crust of the Palythoa in spirit 

 is brown. 



The skeleton. A pinule-fur covers the surface of the body of the sponge. 

 Radial pentactines occupy the subdermal and subgastral layers. Hexactine 

 megascleres are abundant in the interior. Rhabd megascleres and micro- 

 hexactines occur in all parts of the body. In its lower part are met slender, 

 entirely spined pinule-derivate, and mon- to pentactine, ordinary stout and 

 slender acanthophores. The mon- to pentactines with proximally smooth rays 

 are much more abundant than the entirely spined ones. The stalk consists 

 at its origin of nine fairly stout spicules. Four kinds of amphidiscs, all with 

 smooth teeth, can be distinguished : — large and small macramphidiscs, and 



