HYALONEMA (PRIONEMA) AGUJANUM. 253 
GASTRAL AND DERMAL PINULES OF HYALONEMA (PRIONEMA) AGUJANUM. 
Distal ray Lateral rays 
maximum 
thickness, to- 
; basal gether with 
length thickness the spines length 
Me Me Mh Me 
from the 
dermal | basal part of 123-258 8-12 28-35 42-52 
the sponge 
from the 
middle and 
form pinules | upper part 200-311 8-10 30-37 36-48 
ue A of the 
tenuis eee 
gastral pinules 251-300 9-11 30-39 40-52 
dermal and! gastral —'l\ 423-800 8-12 28-39 36-52 
pinules 
form Be ee 225-311 7-10 18-30 37-45 
pinules 
dermal pinules 218-302 7-11 22-36 32-57 
ee tite gastral pinules 215-300 7-13 | 25-38 30-50 
ee a 
esate enh ease 215-302 7-13 22-38 30-57 
pinules 
Besides the dermal and the gastral pinules described above, a considerable 
number of other pinules were found adhering to the surface or embedded in the 
superficial parts of the sponge. Some of these have long and bushy distal, and 
very short lateral rays. In others the distal rays are quite short and very 
slender and the laterals long. The former, which are quite frequent, resemble 
the pinules of Hyalonema tenuifusum and probably belong to that sponge, which 
was trawled at the same station; I accordingly consider them as foreign. The 
latter are rare. They may be proper to the sponge and would, in that case, 
have to be considered as transitions between the dermal pinules and the micro- 
hexactines. Dermal transitional pinules, if such, have been found in both forms 
of var. tenuis and in var. lata. The dimensions of the few observed are :— 
1 The single specimen of var. tenuis form B is not sufficiently well-preserved for a reliable distinction 
between dermal and gastral pinules; hence special measurements are not given. 
