EXPLANATION OF PLATE VIII 



SPONGIA 



Figs. 1-10. Acerate skeletal spicules of monactinellid sponges. (Doppelspit^er 

 Vosmaer.) Figs. 1-7 are enlarged 3o diameters ; figs. 8, 9, 10 X 100 

 diameters. 



Figs. 1 1-17. Acuate orstyliform spicules codifièrent species or monactinellid sponges 

 (Stifty V). Fig. 17 is microspined and shows the axial canal X 100. Figs. 

 14-15 X 3o; figs. 11, 12, 1 3, 16 X 60. 



Fig 18. Microspined acerate spicule X i5o. 



Figs. 19. 20. Microspined styiiform spicules. 19 X 60; 20 X 100. 



Figs. 21-26 Spinulate spicules (Stecknadel, VAof différent species ot monacunellid 



sponges. Figs 22, 25 X 3o ; figs. 24, 26 X 60; fig. 21 X 100. 

 Figs. 27, 28, 29 Anchorate rlesh-spicules ot monactinellid sponges (Anker, V.). 



Figs 28, 29 X 200; 27 X 3oo. 

 Fig. 3o. Hookshapêd rlesh-spicule of Esperella, sp. (Haken, V.) X 00. 

 Fig. 3i. Clasp-hook rlesh-spicu'e of Hamacantha, sp. (Pjlugscharspangen. 



V.) X 200. 



Fig. 32. Sceptrellaor chess-man rlesh spicule, of the genus Sceptrella. X 3oo. 



Figs. 33-43. Curved cylindrical spicules (Stab, Y.) ot diflerent species of monacti- 

 nellid sponges. some probably belonging to the genus Reniera. Figs. 3~, 

 38 X 3o ; 33-36, 39-43 X 60. 

 [n figs. 41 , 42, the axial canals are shown. 



Fi£. 44. Acerate fusitorm skeletal spicule. showing the axial canal, X 3o. 



Figs. 4D-53. Calthrops or tour-rayed spicu es ot Tetracunellid sponges, probably 

 belonging to the genus Pachastrella ( \'ierstrahler,\ ) (Spanische- Reiter) . 

 Figs. 45, 47. 48, 5o, 53 X 3o ; 46, 49, 5 1, 52 X 60. 



Figs. 54, 55. Trifid or zone spicules (Uegabelte Spitpviiikler, V.) in which the 

 summit or head-rays are biturcate and horizontally extended, and the 

 shaft isreduced. Probably belonging to Stelletta, sp. In fig. 55, the axial 

 canals are shown X 3o. 



Figs 56-70. Trifid or zone spicules ol différent species ot Tetractinellid sponges, 

 belonging to Geodites and al lied gênera. In many ofthe forms rigured the 

 shafts are incomplète. Fig. bô a represents a portion of a shaft, X 20, and 

 the trilid head-rays are wanting. Figs. 56-58, 60, 6i,63X3o; figs. 59, 

 62. 64 70 X 60. 



Figs 71-76. Globate or renitorm spicules, (Kugel, Y.) ot the dermal layer of 



Geodia. Fig. 7 1 X 3o ; 72-76. X 60. 

 Figs 77 80. Stellate and globostellate spicules, (Stem, Kugelstern, Y.) probably 



belonging to Tetliya and allied gênera Ail X 100. 

 Figs. 81 Spiral many-rayed snicule (Spiralstern, V) probably belonging to Spiras- 



trella. X 200. 



Figs 87, 88. Irregular skeletal-spicules ofMegamorine Lithistid sponges, belonging 



to Doryderma and allied gênera. Figs. 82 85, 87 X 3o ; 86 X 60. 

 Fig .^9. Elongate skeletal-spicule of Carterella, sp., X 3o. 



Fig 90 92. Nodose skeletal-spicules ofa Lithistid sponge, probably ot Plintliosella. 



Fig. 90 X 3o ; 91 , 92 X 60. 

 Fig. 93. Skeletal spicule of Rhizomorine Lithistid sponge X 200. 

 Fig. 94. Dermal spicule of Lithistid sponge, of the type of Discodermia X 3o 

 Figs. 95-101. Skeletal-spicules of Lyssacine hexaciinellid sponges. Figs 95-98, 100. 



101 X 3o ; Fig. 99, X 200 is probably a rlesh-spicule. 

 Figs 102. io3. Fragments of the spicular-mesh of Dictyonine hexactinellid 



sponges X 60. 



Fig 104. Scopiform rlesh-spicule (Besengabeïn, V.) ot hexactinellid sponge. The 



shaft in this spécimen is broken off close to the head-rays X 100. 

 Figs. io5, 106. Fragments ot dermal spicules of Rossella, sp. When entire, the 



spicules consist of a long rod-like shaft with four pointed rays extending 



from its summit at right angles X 3o. 

 Fig. 107. Portion of an amphidisc rlesh-spicule, probably belonging to Hvalonema 



X 100 



RADIOLARIA 



F.gs. 108, 109 Dictyomitra muiticostata, Zittel X 100. 



