295 



elegans ¥. E. Seh. and H. yracile F. E. Sch. are distinguished by the 

 possession of macramphidisks with half-egg-shaped umbrellas and long 

 teeth. H. »lasotdha^s autodermal pinuli with poplar-tree-like pinular rays ; 

 and finally, H. lamella F. E. Sch. has its macramphidisks scattered in 

 the parenchyma, whereas those of H. dri/galskii are vertically orientated 

 at the surface. Special features of the new species are : — the small 

 size of the macramphidisks, and the total absence of auto-gastral pinuli. 

 Locality. Station 24. XI. 1903. 2725 m. 



2. Caulophacus antarcticus n. sp. 



The stems of 18 examples of an undescribed species of Caulophacus 

 were obtained from 2725 — 3397 m. Nothing of the sponge body re- 

 mains ; but in several of the hollow stems some dried mud was found 

 containing spicules commonly occurring in species of ( 'aidophacus. The 

 stems ranged in length from 4 mm to 21 cm. Most of them had a sharp 

 curve above the basal disk, and several had one or two supplementary 

 disks of attachment along the stem, giving the impression of a repent 

 habit of growth. 



The spicules of the stem are long diactines, which have become 

 joined by innumerable bands of synapticula. The outer fibres of the 

 stem are longitudinal, the inner oblique and transverse. Most of the 

 diactines are swollen and rough at both ends, some only at one end. 



The following spicules were found in the mud inside the stems: — 

 Pentactins. Pinuli, probably autogastral, with pinular ray 214 a long 

 and 7,5 u broad at base, and 26 n broad (including spines) near the 

 apex; smooth above base, then with scattered short spines for more 

 than half the length, and finally with thick incurved spines up to, or 

 nearly as far as, the summit. Tangential rays, 81 X''')^,«, slightly 

 bent away from the outer radial ray, with rough surface, especially at 

 the ends, which may be pointed, or more or less rounded. With a 

 smooth rounded knob in place of an inner radial ray. These spicules 

 are probably auto-gastral and not auto-dermal, because in the seven 

 known species of Ckiidoplmcus and in the doubtful C. oviformis F. E. 

 Sch. the auto-dermal pinuli are hexactins. Pentactin auto - gastralia 

 with a proximal knob are found in C. agassr.ii F. E. Sch. and C. valdi- 

 riae F. E. Sch., and similar spicules without the knob, in C. latus F. E. 

 Sch,, but the pinuli of the new species are at once distinguished from 

 those of the three mentioned , by having a club-shaped outer radial ray 

 in place of a slender tapering one. One example of a pinul was found 

 with a radial ray 412 it long, and finely spined at the end. 



Pentactins (hypodermal or hypogastral) with smooth tangential rays 

 149 X 6,25 //, rough only at ends. 



