SPONGES. 245 



PLATE XL 



Fig. 1. Paresperdla bidentata ; R.N. 263a. Spicules, x530. 



a., tylostyle with bidentate apex; &., 6., serrated sigmata; c, anisoehela, side view; >/., 

 anisochela, front view. 

 2. Paresperella serratohamata ; R.N. 220c. Spicules, x 530. 



n., tylostyle with mucronate apex; /., h., serrated sigmata. 

 ,, 3. Paresperella, sp. Gigantic serrated sigma, x 230. 

 1. Echinodictynm clathmtum ; R.N. 325. Spicules, x 230. 



ii., large stylus; &., slender stylus; c, </., oxea ; >.,/., spined tylostyli. 

 5. Rfynlla tenuissima ; R.N. 234a. Spicules, x 530. 



a., polytylote ; 6., spined tylostyle; ''., isoehela, front view; i/., isochela, side view. 

 ,, 0. Esperella crassissima ; R.N, 240. Spicules., x 230. 



a., tylostyle; /'., anisochela, side view; c, anisochela, front view; <l., sigmata; <>., fcricho- 

 dragmata. 

 ,, 7. Raspailia h&rnelli ; R.N. 59. Spicules, x 230. a., large stylus; &., c, small surface styli; d., e., 



/., ;/., oxea ; h., Ii., strongyla ; /.-., /., m., spined subtylostyli. 

 8. Histoderma vesicidatwm ; R.N. 212a. Part of dermal skeleton, x 230. 



"., ., o., oxea; ->'., s., strongyla. 

 ,, 9. His/, nlmiiii i-rsii iihitiim .- R.N.. 212a. Isochelse, x 460. a., side view; h., front view. 



PLATE XII. 



Fig. 1. Spongosorites topsenti ; R.N. 152. Spicules, x 52. 



a.-k., various forms of large megascleres ; /., two small oxea; in., intermediate form. 

 ,, 2. Spongosorites (1) lamellata ; R.N. 236. 



a. b. c, styli, x 52 ; d., two small oxea, x 52 ; c, small oxeote, x 230. 

 ,, 3. SpoTU/osorites (1) lapidiformis ; R.N. 145. Spicules, x 79. 

 ,, 4. Hymeniacidon petrosioides ; R.N. 151. Spicules, x 230. 

 ,, 5. Tkrinaeophora dwrissima ; R.N. 355. Spicules, x 230. 



a., stylote; b., oxeote; ''., </., trichodragmata. 

 6. Tlniiitiri'jiliiiiit agariciformis ; R.N. 160a. Spicules, x 230. 



a., !>., <\, styli; '/., c, oxea; /'., trichodragmata. 

 7. Axinella haiichandrioides ; R.N. 75. Spicules, x 230. a., oxeote; 6., c, stylote. 

 ,, 8. Axinella manus ; R.N. 53. Spicules, x 230. 

 ,, 9. Agelas ceyhnica ; R.N. 312. Spicules, x 230. 

 ., 10. Hlnihih',1 nun indica; R.N. 341. 



a., b., i'., rhabdostyli, x 230; </., minute spined styli, x 530; e., contort sigmata, x 530. 



PLATE XIII. 



Fig. 1. OoUocalypta digUata ; R.N. 74. Oxeote spicule from body, x 230. 

 2. R.N. 74. Part of transverse section of a digitiform process, x 52. 



ii.r., axial skeleton of spicules and spongin; d.p., position of dermal pores; ect., collenchy- 

 matous ectosomal tissue; I.e., longitudinal canals; sept., septum between two longitudinal 

 canals. 

 3. Phakellia symmetrica ; R.N. 159. Spicules, x 230. a, b, short styli; c, oxeote; d, long stylus. 

 4. Axinella tenuidigitata ; R.N. 202A. Styli, x 79. 



5. Phakellia ceylonensis ; R.N. 34. Spicules, x 230. a, b, styli ; c, d, e, oxea. 

 ,, 6. Phakellia crassistylifera ; R.N. 256. Three spicules, x 230. 



