11 



Both specimens are tulip-sliaped, abruptly truncated terminally, 7 cm. loug, 

 and 4 cm. broad above. The oscular sieve-plate is circular, flat, and raised 

 towards the margin, which slightly protrudes upwards and outwards as a free 

 sharp edge. The pores of the sieve-plate are numerous, more or less circular and 

 1-2 mm. wide. The principal skeleton-net is fairly well preserved, its meshes are 

 small and quadratic. In one specimen the root-tuft (peduncle) projecting from 

 the lower, attenuated end of the body is complete, cylindrical, over 18 cm. lono- 

 and nearly 8 mm. thick. The upper, spirally-twisted part of it is covered with a 

 continuous Palythoa-crust for a distance of at least 14 cm. (pi. Ill, f. 1). Below 

 the spicules composing it are isolated and diverge slightly. The sponge-bodv is, 

 in spirit, light clay-coloured. The most numerous parenchymal macroscleres 

 are oxydiactines. These are smooth, straight or shghtly curved, and have a 

 central inflation more or less clearly defined, which sometimes bears four tubercles 

 arranged crosswise. The length of these oxydiactines is very variable, generally 

 1-2 mm., and they are usually 5-20 /* thick (pi. Ill, f. 2). 



Less frequently oxyhexactines occur. Their rays are nearly equally long, 

 smooth, 30-40 /^ thick and gradually attenuated towards the sharp pointed end. 

 Also monactines, with the blunt end occasionally inflated, sometimes even pinhead- 

 like, are met with. In the subdermal oxypentactines, which form an important 

 part of the supporting skeleton, the paratangential basal rays are considerably 

 shorter than the radial ray which measures 50 /^ and more in length (pi. Ill, f. 2, 

 pi. IV, f. 2). 



In well-preserved specimens one clearly sees that the acanthophores near 

 the lower end of the body are chiefly composed of cross-shaped tetractines and 

 straight diactines. Acanthophor-hexactines, -pentactines and -triactines are less 

 frequent. All the superficial acanthophores are small, entirely covered with uni- 

 formly developed spines, and appear as if covered with crystallised sugar. Fur- 

 ther in the interior they are longer, frequently curved, and bear spines on the 

 inflated, terminal parts of the rays only. 



The diactine marginalia forming the fringe of the oscular margin are not 

 more than 100-120 /* long. The proximal ray of these spicules which is im- 

 bedded in the body of the sponge is perfectly smooth, the distal free ray spined, 

 the spines decreasing in size towards the distal end of the spicule, the terminal 

 part of which again appears smooth. The centre of the spicule bears four rounded 

 protuberances arranged crosswise and containing rudiments of axial canals. 



The long basalia- spicules of the root-tuft attain a thickness of 500 /" and 

 are either quite smooth or covered in the greater part of their length with very 

 oblique closely " anliegenden " spines. These are arranged in a somewhat irregular, 

 often interrupted, spiral line. As the root-tuft is preserved only in one of the 

 specimens and as its lower end is torn off also in that one, I could not observe 

 the anchor-teeth at the ends of these spicules. 



