77 



here has a maximum transverse diameter of 18 m. The distal ray is smooth 

 only basally and covered with scale-like processes directed outwards for the rest 

 of its length. The five other rays are quite smooth or only sparsely covered 

 with small, pointed protuberances. They are much thinner than the distal ray 

 and gradually attenuated towards the sharp-pointed end. The proximal ray is 

 about half as long as the distal ray, the paratangential rays are longer than this, 

 but hardly attain the same length as the distal ray. 



The hypodermalia have on the whole a similar shape. The radial, distal ray, 

 which penetrates the parenchyme in a direction vertical to the surface, is usually as 

 long as the freely projecting proximal ray, sometimes it is even considerably longer. 



The excurrent canals, which open out into the gastral cavity, are surrounded by 

 pretty large, radially arranged oxyhexactines with sHghtly rough rays, 200 /^ long. 



The intermediary parenchymalia are represented by two different kinds of 

 hexasters, larger discohexasters about 150 /^ and smaller plumicoms, about 80 ^ 

 in diameter. The former are more numerous than the latter. The discohexasters 

 have short and stout main-rays with thick, circular terminal discs, which bear 

 about 12 branch-rays on their flat or slightly convex outer surface. About eight 

 of the branch rays are usually attached to the marginal part of the terminal disc, 

 whilst the others are scattered over its central part (pi, XIII, f. 4,9,10). The 

 branch-rfvys are smooth, filiform, proximally rather stout but very slender half way 

 up, towards the end they are thickened in a club-shaped manner and terminally 

 extended to form a transverse, watchglass-like, convex circular disc, 10-12 /^ 

 in diameter, from the margin of which 16-18 slender, pointed teeth 3-4 /^ 

 long, following the curvature of the disc and recurved accordingly, arise 

 (pi. XIII, f. 5, 6). The bundles of branch-rays are spirally twisted in a most 

 unusual and remarkable manner through about half a turn (pi. XIII, f. 4, 10.) 



The plumicoms are met with chiefly in the vicinity of the gastral membrane. 

 They have a considerable central thickening from which six stout and short 

 main-rays arise; these extend terminally in a mushroom-like manner to form a 

 circular, convex, transverse disc, 12 /^ broad. The margin of the disc is con- 

 tinued in a fine membrane, which is bent upwards and then inwards ; completely 

 closing over the disc and forming a continuous, convex roof over it. From this 

 roof numerous slender branch-rays, arranged in concentric circles, rise vertically. 

 These branch-rays are all gracefully curved outwards, like the petals of a 

 Thalictrum. blossom. Those forming the inner circle are the longest and 

 basally nearly straight. Those forming the outmost circle are the shortest and 

 curved right down to their base. Thus the branch-ray-groups attain the shape 

 of low and broad fountains (pi. XIII, f. 7, 8'. . 



The tubular peduncle is very hard, only slightly flexible. Its skeleton chiefly 

 consists of round and smooth, parallel, longitudinal beams, 20-40 /^ thick, which 

 are numerous and connected with each other by a great number of synapticula, 



