266 



CEYLON PEARL OYSTER REPORT. 



EXPLANATION OF PLATES. 



List of Reference Letters. 



amb.e., amoeboid cell in mesogloea. 



nji.c, aperture of canal. 



on., contracted autozooid. 



lt.cn., battery of nematocysts. 



c.iii.l., capitular marginal lobe. 



r.uii., expanded autozooid. 



r.c, ccelenteric cavity. 



cap., capitulum. 



cap.mar., capitular margin. 



</., clubs. 



col.end., columnar endoderm. 



c.v., ciliated vessel. 



tl.in.f., dorsal mesenterial filament. 



ect., ectoderm. 



end., endoderm. 



end.b.w., endoderm body-wall. 



end.can., endodermal canals. 



g.v., germinal vesicle. 



in.m.sp., inter-mesenterial space. 



l.m.f., lateral mesenterial filament. 



/. lobe. 



m., mesentery. 



in. up., mouth aperture. 



mar.lob., marginal lobe of capitulum. 



mg., mesogloea. 



mg.h.tv., mesogloea body-wall. 



nu/.c, mesogloeal cells. 



uti/.il., dense layer of mesogloea surrounding 



siphonozooids. 

 nuc, nucleus, 

 of., ovum. 

 s., stomodaeum. 

 si., siphonozooid. 

 sp., spicule. 



sp.h., hole left by spicule after decalcification. 

 st., stalk. 

 tmt., tentacle. 



tr.s.c, transverse superficial canal. 

 tu., tubercle-like zooid on the stalk. 

 cm., ventral mesentery. 

 v.m.f., ventral mesenterial filament. 

 i/.aii., young autozooid. 

 i/l\, yolk of ovum. 

 zo., :.'., zoochlorell.'e. 



