Fig. 
Fic. 
Fia. 
Fig. 
Fic. 
Dice 
Fie. 
Fig. 
Fig. 
Fia. 
Fia. 
Fia. 
SYDNEY J. HICKSON anp F. H. GRAVELY. 
. 16.—Lampra parvula. Adult and smaller zooids (xX 1). ¢.p., chitinous pellicle ; f.sp., feltwork 
of sponge-spicules and diatoms in which the basal ends of the zooids are embedded ; yph., gonophores. 
. 17.—Corynidae, sp. B. (X 10). he., hydrocaulus ; Arh. f., hydrorhizal filaments ; iyd., hydranth. 
18.—Myriothela ? (x 2). hrh. f., hydrorhizal filaments ; ¢., tentacles. 
. 19.—Sertularella spiralis. Part of a pinnule (x 25). ac., acrocyst ; ect., ectodermal sheath around 
base of hydranth ; gt/., gonotheca ; op., opercular flaps. 
. 20.—Sertularella spiralis (x 25). Part of main axis, showing method of branching ; br., branch ; 
hth., hydrotheca ; m.d., main axis. 
. 21.—Sertularella plectilis (x 15). gth., young gonotheca; hyd., hydranth ; 7. hth., reduplicated 
hydrotheca ; s. /th., simple hydrotheca. 
. 22.—Dictyocladium fuscum (x 10). hth., hydrotheca ; s¢., stolon helping to bind the colony together 
by anastomosing with another branch. 
. 23.—Plumularia glacialis 9. Central axis and proximal part of hydrocladia (x 20). 9 gth., 
female gonotheca; /’h., hydrothecae ; nph., nematophores ; f. /cl., hydrocladia-bearing tube of 
central axis ; ¢. sp., supporting tubes. 
24.—-Plumularia glacialis 6. Part of a hydrocladium (x 40). 4 gih., male gonotheca; /yd., 
hydranth ; 7. Ael., node of hydrocladium ; nph., nematophore ; sp., sperm. 
PLATE IY. 
25.—Campanularia verticillata, var. grandis (x 2).  he., hydrocaulus; hrh., hydrorhiza ; Ayd., 
hydranth ; s., sponge growing upon the hydrocaulus. 
26.—Campanularia laevis (x 7).  gth., gonotheca; de., hydrocaulus; frh., hydrorhiza; hyd., 
hydranth. 
27.— Halecium arboreum; part of a hydrocladium (x 20). d., dactylozooid; hyd., hydranth ; 
n., node; mph., nematophore; p., perisarc. (The measurements given in the text are of some 
particularly well-expanded nematophores that we discovered after this figure was drawn.) 
28.—Halecium arboreum. ‘Coppinia” mass (x 1). cp.m., “ coppinia” mass ; /.c., hydrocaulus. 
29.—Halecium arboreum. Part of “coppinia” mass (x 15). d., dactylozooid ; gih., gonotheca ; 
nph., nematophore. 
30.—Obelia geniculata (x 3). To show mode of branching. 
31.—Lafoéina longitheca (x 50). d., dactylozooid; Ayd., hydranth; op., opercular flaps ; 
p., pevisare of hydrorhiza. 
32.—Diagrammatie longitudinal section of a male gonophore of Perigonimus antarcticus (xX 50), 
ecl., outer and inner ectoderm of umbrella in contact; ecf. wv. 7, inner ectoderm of umbrella ; 
ect. U. 0., outer ectoderm of umbrella ; end. m., endoderm of manubrium ; end. 7. ¢., endoderm rod 
representing the ring-canal; ms. m., mesogloea of manubrium; ms. /., mesogloeal lamella of 
umbrella ; sp., sperm maturing from within outwards, and completely filling the subumbrella cavity ; 
jt is omitted in the figure at sw. c., to give greater clearness to the different parts of the gonophore. 
33.—Diagrammatic longitudinal section of male blastostyle of Stylactis halecii (X 50). c.y., collar 
of perisarc around base of zooid ; ms., mesoglea ; n¢., nematocyst in the ectoderm; ¢., tentacle 
(entirely ectodermal) ; other letters as in fig. 32. 
34.—Diagrammatic longitudinal section of male gonophore of Tubularia hodysoni (xX 50). 
Letters as in figs. 82 and 383. 
35.—Diagrammatic longitudinal section of female gonophore of Lampra parvula (x 30). end. u., 
endoderm of umbrella ; ov., ovum lying amongst the other rounded and deeply staining cells of the 
endocodon ; ov. rup., ovum rupturing the “umbrella” and protruding part of its substance through 
to the exterior ; other letters as in figs. 32 and 33. 
