SPONGIIDA. 
10 Spong. 
after the birth of the embryos. The hinder pole of the embryo becomes 
ciliated after birth, and develops a temporary depression, probably repre- 
senting a primitive mouth ; the embryo settles on its posterior pole, and 
then applies its side to the object to which it becomes fixed. The 
stomachal cavity commences in the interior by recedence of the cells, and 
ultimately breaks its way out, forming an osculum. 
Genesis of acerate spicules, each within a mesoderm cell, in this species, 
(5) p. 328. 
Starch cells detected in it, (5) p. 323. 
Sabella and Stephanoscyphus found living commensally in it, (5) p. 327 . 
Echinonemata. 
Dictyocylmdrus laciniatus and pyhii^ Carter, (1) pp. 296 & 297, pi. xxvii. 
fig. 14, Mauritius. 
Trikentnon \_Tricentrium] Iceve^ id. 1. c. p. 294, pi. xxvii. figs. 9-12, West 
African Coast. 
Plectronella, Sollas, (12) p. 17, P. papillosa^ id. 1 . c. pis. iv.-vi. Echino- 
nematous, branching ; skeleton spicules acerate, smooth ; fiesh spicules 
undulating; echinating spicules triradiate, the projecting ray roughened 
and blunt; marine, habitat ? ; the echinating spicules have branches from 
the central canal projecting into them. 
Latruncula corticata, Carter, (1) p. 298, pi. xxvii. figs. 1-4, said to be 
from the Red Sea. 
Ithaphidistia spectahilis^ Carter, (1) p. 300, pi. xxvi. figs. 10, 13 & 14, 
Mauritius. 
Hymerrhaphia spiniglohata^ Carter, on Stylaster sanguineus, South Sea ; 
(1) p. 301, pi. xxvi. figs. 16 & 16. 
Trachycladus, Carter, (1) p. 343, referred to group Pluriformia of 
fam. Pctyonida. T. Icevispirulifer, id. 1. c. pi. xxviii. figs. 1-5. Of shrub- 
like external form; skeleton spicules smooth, acerate; flesh spicules 
minute, smooth, vermicular, and minute, smooth, bacillar. South 
Australia. 
Plocamia plena, Sollas, (13) p. 44, pis. vi. & vii. Sarcode bright yellow 
when dry. West Africa, Lat. 15*^ S. No horny matter present. 
Holorrhaphidota. 
Amorphina stellifera, Carter, (1) p. 344, pi. xxix. fig. 10. Has minute 
stellate flesh-spicules. Coloured pink by an Alga resembling Palmella. 
South Australia. 
Pharetronema, Sollas, (12) p. 404. Reuierid. Allied to the fossil 
Pharetrospongia. P. zingiheris, id. 1. c. pi. xxx. Fibres of internal net- 
work composed of smooth acerate spicules; they radiate to exterior, 
where they meet and arch over to form dermal network, which bears 
prominent pencils of spicules. Flesh spicules very fine, filiform. 
Jamaica. Varieties of the acerate spicules, p. 406, exhibit various forms 
of the point, and also show budding. 
Rhaphidotheca affinis, Carter, (2) p. 497, pi. xvii. a, figs. 1 & 3. On 
Amphihelia oculata. Atlantic, north of Scotland. 
Suberites spinispirulifer. Carter, (1) p. 345, pi. xxviii. figs. 6 & 7, Port 
Elizabeth, Cape of Good Hope. 
