PLATE V. 



Pag. 



figs, i 4 Ragaclinia annulata n. sp. Different forms of single 



and combined skeleton spicules. Fig. 3. shows two 



of the spicules attached together 4 j 58 



figs, j" 8 Racodiscula and allied genera. Detached and com- 



bined skeleton spicules. Fig. 7 shows a portion of 

 the skeleton with the spicules naturally attached 



together 4 T 60 



figs. 9, 10, loa, n Stauractinella cretacea n. sp. Free skeletal spicules 70 

 figs. 12 16 Hyalostelia fusiformis. Free skeletal spicules ... 71 



Fig. 17 Leptophragma, sp. Fragment of the skeletal mesh . 65 



fig. 1 8 Leptophragma, sp. Skeletal mesh with solid nodes 66 



fig. 79 Craticularia sp. Skeletal mesh with solid nodes . . 66 



fig. 20 Cystispongia sp. Skeletal mesh with solid spherical nodes 67 



fig. 21 The same. Surface layer of the skeletal mesh . . 67 



fig. 22 Coscinopora, sp. Fragment of the skeletal mesh with 



lantern nodes 68 



fig. 23 The same. Portion of the outer membrane .... 68 



fig. 24 The same. Fragment of the root-fibres 68 



fig. 23 Ventriculites ? sp. Portion of the surface membrane. 69 



fig. 26 The same. Fragment of skeletal mesh with lantern 



nodes 69 



fig. 27 Spined shaft of anchoring spicule of Hexactinellid 



sponge 72 



figs. 28, 29 Spicules showing irregular tubes or borings in their 



interior \ 73 



fig- 30 Trifid spicule, showing infiltration of the inner por- 



tion of the spicule, as well as of the canal .... 14 



figs, i 8, 28, 29 are drawn to the scale of 40 diameters the rest 

 of the figures are on the same scale of 20 dia- 

 meters. All are drawn by means of the Camera lucipa. 



