30 



times the central cone is so excentric that it coalesces in its entire length with 

 the wall of the calyx, in which case only 1-3 septa are developed (pi. VII, 

 f. la). 



The root-tnft or peduncle is more or less intact. Its length and thickness 

 is on the whole proportional to the size of the body. In the largest specimen 

 the upper, firmly spirally twisted part of it is 2 mm. thick, and down to the 

 broken end it is 7 cm. long (pi. VII, f. 11). In most specimens an annular 

 Palythoa-crust with 1-7 polyps is met with on the upper end of the peduncle, 

 just below the body of the sponge. 



On the outer surface a dermal reticulation with quadratic meshes, the size 

 of which increases with the size of the sponge, can always be traced. This 

 network is exceptionally clearly visible in the specimen represented o:i pi. VII, 

 f. 11. The gastral surface is perforated by round apertures, up to 1 mm. wide 

 and surrounded by smooth margins ; it is much more smooth than the outer 

 surface. 



The spicules of these young specimens of Hi/alonema affine reticulatum resem- 

 ble in most points of their arrangement, size and shape the spicules of fuUgrown 

 specimens. I will here dwell on those peculiarities of them only which I con- 

 sider as expressions of differences of age. 



In shape the macroscleres are similar to those of fuUgrown specimens. 

 Their length and thickness chiefly depends on the size of the sponge. All the 

 macroscleres of the smallest specimen are much shorter and more slender than 

 those of the largest (pi. A"II, f. 11), the latter being about the same size as those 

 of fuUgrown individuals. 



It is to be remarked that the dermal pinules have in all the twelve speci- 

 mens the same shape and are slightly longer than in the fuUgrown specimen 

 described above. In this, as in the Japanese specimens, they are always over 

 200, on an average 300 /" long. The same applies to the macramphidiscs, which 

 are in these young specimens always over 200 m in length. The size and abund- 

 ance of the mesamphidiscs, spicules of well known inconstancy, are subject to 

 great variations. In some of the specimens they are abundantly present in 

 many different forms, in others they are absent altogether. On the other hand 

 iLicramphidiscs, of the typical form but very variable in size, 20-40 /* long, are 

 always found in the dermal membrane. 



Of these twelve specimens two, the large one figured in fig. 11 and a on 

 plate VII, and a smaller one 20 mm. long, were found in the Andamans near 

 Jforth Sentinel Island in a depth of 458 m. = 250 fths. The other ten smaU 

 specimens were also captured in the Andamans near Ross Island, which is not 

 very far from North Sentinel, in a depth of 485 m, = 2G5 fths. 



