34 SYDNEY J. HICKSOX AND F. H. GRAVELY. 



Fro. 1G. Lampra parvulu. Adult and smaller zooids (x 1). r.p., chitinous pellicle: f.sp., feltwork 



of sponge-spicules and diatoms in which the basal ends of the zooids are embedded ; i/ph., gonophores. 

 FIG. 17. Corynidae, sp. B. (x 10). hr.., hydrocanlus ; hrh.f., hydrorhizal filaments; liyd., hydranth. 

 FIG. is. Mijriothcla ? (x 2). hrh.f., hydrorhizal filaments ; t., tentacles. 

 FIG. 19. SerttilarMit spiral is. Part of a pinnule ( X 25). fie., acrocyst ; ecf., ectodermal sheath around 



base of liydranth ; gth., gonotheca ; op., operculnr flaps. 

 FIG. 20. Sertiilnri'llit xpiralis ( X 25). Part of main axis, showing method of branching; hr., branch ; 



hth., hydrotheca ; in. a., main axis. 

 FIG. 21. Sertularella plectilis (x 15). gth., young gonotheca; hyd., hydrauth ; r. hth., reduplicated 



hydrotheca ; s. hth., simple hydrotheca. 

 FIG. 22. Dktyocladium fwcum (x 10). /;//*., hydrotheca ; st., stolon helping to bind the colony together 



by anastomosing with another branch. 

 FIG. 23. Pltmittlaria gMwlis ?. Central axis and proximal part of hydrocladia (x 20). <? t/th., 



female gonotheca; li'h., liydrothecae ; nph., neniatophores ; /. hcL, hydrocladia-bcaring tube of 



central axis ; t. sp., supporting tubes. 

 FIG. 24. Pliiiniiliiri/i t/hiciitlis &. Part of a hydrocladium (x 40). $ gth., male gonotheca; hyd., 



hydranth ; n. ltd., node of hydrocladium ; nph., nemabophore ; sp., sperm. 



PLATE IV. 



FIG. 25. Cctmpanidaria rerlicillttltt, var. grandis (x 2). hr., hydrocaulus ; hrh., hydrorhiza ; hyd., 



hydranth ; s., sponge growing upon the hydrocaulus. 

 FIG. 26. Campanularia Inevis (x 7). gth., gonotheca; he., hydrocaulus; hrh., hydrorhiza; hyd., 



hydrauth. 



FIG. 27. Hahcium arhoreitm ; part of a hydrocladium (x 20). d., dactylozooid ; hyd., hydranth; 

 n., node ; nph., nematophore ; p., perisarc. (The measurements given in the text are of some 

 particularly well-expanded neniatophores that we discovered after this figure was drawn.) 

 FIG. 28. Haleciiimarbureu.ui. " Coppinia " mass ( x 1). cp.m., " coppinia" mass ; //.r., hydrocaulus. 

 FIG. 29. Haleciitm arboreum. Part of " coppinia " mass ( X 15). d., dactylozooid ; yth., gonotheca ; 



nph., nematophore. 



FIG. 30. OMia yenictdata ( x 3) . To show mode of branching. 

 FIG. 31. Lafoeina hinyitheca (x 5o). d., dactylozooid; hyd., hydranth; op., opercular flaps; 



p., perisarc of hydrorhiza. 



FIG. 32. Diagrammatic longitudinal section of a male gonophore of Periyonimus antarcticus (x 5o). 



vcL, outer and inner ectoderm of umbrella in contact ; act. //. i., inner ectoderm of umbrella ; 



ect. v. o., outer ectoderm of umbrella ; end. m., endoderm of mauubrium ; end. r. c., 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 ; 



it is omitted in the figure at su. >'., to give greater clearness to the different parts of the gonophore. 



FIG. 33. Diagrammatic longitudinal section of male blastostyle of Stylactis halecii (x 50). c.p., collar 



of perisarc around base of zooid ; ms., inesoglcea ; nc., uematocyst in the ectoderm ; t., tentacle 



(entirely ectodermal) ; other letters as in fig. 32. 



FIG. 34. Diagrammatic longitudinal section of male gonophore of Tubulnria hndjsoni (x 5o). 



Letters as in figs. 32 and 33. 



FIG. 35. Diagrammatic longitudinal section of female gonophore of Lampra pctmula (X 3o). end. H., 

 endoderm of umbrella ; ov., ovum lying amongst the other rounded and deeply staining cells of the 

 cndocodon ; ov. ri/p., ovum rupturing the "umbrella " and protruding part of its substance through 

 to the exterior ; other letters as in figs. 32 and 33. 



