390 
My. T. Higgin on two Heaactinellid Sponges. 
Fig. 2. Portion of dermal latticework, showing the relative position of 
Fig. 3 
_ Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
ev 
Fig. 
Fag. 
Eig. 
Fug. 
4, 
. Small sexradiate spicule, the arms spined towards their ex- 
6 
dc 
8 
9 
the spicules of which it is composed: aaaa, arms of large 
nail-hke spicule ; sss, shafts of the same; d, sarcode stretched 
across the mesh; p, pores; ¢, feathered spicules (no, 8) in situ. 
Diagrammatic. 
. Sparsely spined acerate spicule, the spines pointing towards the 
middle of the spicule. 
Crucial spicule, with points of arms barbed like a harpoon. 
tremities; the spines bent upon themselves, pointing towards 
the ends of the arms. 
. Slender birotulate with eight arms at each end, the shaft studded 
with short blunt spines throughout its entire length. 
Minute birotulate generally with eight arms at each end, in great 
quantities throughout the sponge. 
. Crucially headed plumose spicule of the latticework. 
. Free end of one of the spicules of the glass rope. 
10. Free end of one of the spicules of the glass rope of a Japanese 
1 
2. 
9 
v0. 
ITyalonema, in the possession of the Liverpool Free Museum 
(no. 10. 9, 68, 1). 
PLATE XXII, 
Large acerate spicule from surface of Zyalonema cebuense, similar 
to that found in the stem of Crateromorpha Meyer; it is also 
found in LHyalonema Steboldii, not, however, on the surface, 
but in the interior structure round the cord. It measures 
about 4-12ths of an inch in length by 1-G6th in its broadest 
art. 
“‘ Spinicrucial ” spicule from base of sponge-head of Hyalonema 
cebuense, in great quantity about the cord; length of each arm 
4-500ths to 56-500ths of an inch. 
Lubaria hemispherica, Gray, after a photograpb by Robinson and 
Thompson. 
3A. Anchoring-spicule of Labaria hemispherica, drawn to the scale 
of 1-500th to 1-8th of an inch. 
Fg. 4, Large nail-like spicule from the surface-reticulation of the same. 
Shaft 3 an inch in length, with a diameter of 1-48th of an inch 
at the head; length of arms 3, 3, 4, 4 inch respectively. 
Figs. 5-7. Plumose spicules, extreme forms, there being many varieties 
of intermediate shape; measuring from 2-500ths to 10-500ths 
of an inch in height or length of plumose shaft. 
Figs. 8-14. Some of the spicules of the general structure : 8,9, 10 measure 
on an average 1-10th of an inch in length; 11 is peculiar to 
the species, and measures generally 8-500ths of an inch in 
length ; 12 and 15 are drawn to the scale, viz. 1-500th to 1-8th 
of an inch (18 supposed to be an immature form of 12); 
14 measures 3-500ths of an inch from the point of one arm to 
the point of the arm opposite. 
