24G CEYLON PEARL OYSTER REPORT. 



Fig. 7. Airirtta elrmgata ; R.N. 73. Spicules, x 79. , /', styli ; c, oxeote ; d, r, f, strongyla. 

 8. Lfiiroxolenin ewiacea, var. iTi/lnm-nxi* ; R.N. 377. Spicules, x 360. 



a, I, c, triradiates ; <l, portion of oxeote. 

 9. 1.1-iK-iixiilt'itin fi'iuii/iUasii ; RN. 158. Spicules, x 360. a, triradiate ; //, quadri radiate, facial view; 



r, quarlriradiate, side view, showing .apical ray ; d, part of oxeote. 

 , 10. Leuramlm donnani ; R.N. 186. Spicules, x 79. 



a, I, parenchym.il triradiates; c, d, dermal triradiates; e,f, gastral quadriradiates ; g, oxeote. 



PLATE XIV. (All the figures from photographs.) 



Fig. 1. Hirdnia fusca; part of R.N. 48, x H. 



2. Hippospongia clathrata ; R.N. 24, x-[. 



3. Evxpongia officinalis, var. ceylonensis ; R.N. 37 A, x about H. 



,, 4. Spongelia elasiica, var. a-axita ; R.N. 35, x about f . 



5. Hirdnia anomala ; R.N. 13, x about H. 



C. Phyllospongia papi/racea, var. ; R.N. 104A, x 11. 



7. Meyalopastas nigm ; R.N. 71, x. 



PLATE XV. 



Fig. 1. DanrineUa simplex ; R.N. 302. End of primary fibre, enclosed in conulus, x 230. 



,, 2. Danemella simplex ; R.N. 302. Portion of primary fibre, in which the pith (p.) is partially replaced 

 by fungal (?) filaments (/.), x 230. 



,, 3. Megalopastas pulvilhis ; R.N. 191. Portion of skeleton as seen in vertical section, showing the old 

 apices of primary fibres (ap.) enclosed in younger portions of the fibres, x 79. 



4. Diagrammatic sketch of the general anatomy of the genus Megalopastas, based upon vertical 

 sections of a specimen of M. elegant ( = Dendrilla elegans, LENDENFELD) from Port Phillip 

 Heads, Australia, x 52. r., surface eomili ; e.c., embryo capsules ; em., embryo ; er.c., exhalant 

 canals; f.c., flagellate chambers; i.e., inhalant canal; p./., primary skeleton fibres; p.*., pore- 

 sieves ; s.c., subdermal cavities ; s.f., secondary skeleton fibres. 



5. Megalvpastas nigm; R.N. 161A. Part of skeleton, as seen in vertical section, including the dermal 

 skeleton (il.s.) as well as the main skeleton, x 52. 



,, 6. Megal-opaatas nigra ; R.N. 161A. Dermal skeleton, x 52. 



7. Megalopastas nigra ; R.N. 161A. 



End of primary fibre, showing mode of growth and origin of secondary fibres, x 230. 



8. Megalopastas nigra; R.N. 161 A. 



Origin of new primary fibre from a secondary fibre of the dermal skeleton, vertical section, 

 x 230. c., surface conulus ; (/.*., dermal skeleton ; p./., new primary fibre. 



PLATE XVI. 



Fig. 1. Hirdnia anomala ; R.N. 82. Part of skeleton, as seen in transverse section, x 52. 

 2. Hirdnia luberosa ; R.N. 88A. Part of skeleton, as seen in vertical section through the surface, 



including the sand-cortex (s.c.), x 52. 



,, 3. Hirdnia schuhei ; R.N. 277.^ Part of skeleton, as seen in vertical longitudinal section, x 52. 

 4. Aplysina lierdniani ; R.N. 340. Part of skeleton, as seen in vertical section of body, x 79. 

 ,, 5. Eusptmgia iifUnmilia, var. rri/lonensis ; R.N. 101. Part of skeleton, as seen in vertical section, x 79. 



