/ 



whole similar to the dermal ones. Their basal rays are a little longer, measurino- 

 on an average 70 /^. Their distal ray measures about 100 /-t in length. Such a 

 diversity in shape and size as in the dermal pinules is not met with here. Canalar 

 pinnies are in this, as in other species of Pheronema, nearly entirely absent ; only 

 rarely one finds very slender pentactine or hexactine pinules, with sparsely-spined 

 distal ray, in the canal- walls. 



Amphidiscs of two kinds, macramphidiscs and micramphidiscs, are met with 

 in the dermal membrane. Mesamphidiscs seem to be absent. The Macramphidiscs 

 are 300-350 ^ long, and have bell-shaped terminal discs which attain a dia- 

 meter of 80 and a height of 70/^. The shaft is 12^ thick, smooth at the ends 

 but roughened by a few rounded tubercles in the central part. Each disc has 

 eight broad, spade-shaped, terminally-rounded marginal teeth (pi. I, f. 3). 



The numerous micramphidiscs are 30, rarely as much as 40 /* long. Their 

 terminal discs are bell-shaped, 8 ^^i long, 8 /* broad, and have eight or twelve 

 marginal teeth. The shaft is rough. The amphidiscs of the gastral sieve- 

 membrane and the canal- walls are similar. 



Among the parenchymal microscleres micro-imcinates and micro-oxy- 

 hexactines occur. The micro-uncinates are about 500 M long and covered with 

 short, oblique spines. They vary considerably in size and their shape is similar to 

 that of the large uncinates described above. It might therefore be assumed that 

 the large and the small uncinates are connected by transitional forms and not 

 essentially different from each other. I do not think however that such is the case, 

 and I believe that they really represent two different kinds of spicules because 

 they differ in respect of the position and shape of their spines. In the large unci- 

 nates these spines are long, straight and very oblique, nearly parallel, closely 

 " anliegend " to the shaft. In the small uncinates the spines diverge consider- 

 ably. In the anterior part of the spicule their basal part is nearly perpendicular 

 to the shaft and their distal part strongly bent, so that the spines appear hook-like 

 (pi. I, f. 9, 10). 



The microhexactines are found in the interior in varying quantities. 

 Here and there they are pretty numerous. Their 6 rays are equal, smooth or 

 slightly roughened, usually straight, rarely slightly and irregularly curved, 2-3 h- 

 thick at the base and gradually attenuated towards the sharp end. The whole 

 spicule is 150 /* long (pi. I, f. 11). 



All the specimens of Pheronema raijlianus F. E. Sch. brought home by the 



" Investigator " were found in the vicinity of the Andaman Islands. The two 



^ large specimens described by me in 1895 were captured 12° 37' N., 92° 19' E. in 



depths of 316 m.=184i fths. and 530 m.=280 fths. The small specimen of the 



y* size of a pigeon's egg formerly described by me as Ph. circumpalatum F. E. Sch., 



a quite young specimen of the size of a pea, and a fragment of a specimen 



2 



