dredged up from the Gulf of Manaar . 155 



c, fork and anchor ; d, occasional form of zone-spicule ; e, ex- 

 ternal stellate ; /, internal stellate (Sc. D). The clotted lines at 

 the bottom of a a and b b, respectively, are to show that they 

 are continuations of the same spicules, which, upon this .scale, 

 are too long for the Plate. 



Plate VU. 



Fig. 41. Stelletta euastrum, Sdt., parasitic on a group of Siliquaria 

 anguina : a a, mouths of the Siliquarice (nat. size) ; b, zone- 

 spicule ; c, body-spicule : d, siliceous disk ; e, minute acerate 

 flesh-spicule ; /, minute stellate flesh-spicule (Sc. D) ; g, more 

 magnified views of d, e, and f, respectively (sc. l-48th to 

 l-(3000th) ; h, still more magnified view of acerate flesh-spicule, 

 to show that it is microspined and inflated in the centre ; 

 /, more magnified view of ray of stellate, to show that it is micro- 

 spined ; k, more magnified view of portion of disk, to show 

 form and position of stelliform points on surface ; I, still more 

 magnified views of point, lateral and direct, respectively. 



Fig. 42. The same, Australian specimen : a a a, vents ; b b, pores in the 

 crust (nat. size); c, spined stellate (quadriradiate) (Sc. B). 



Fig. 43. Tisiphonia nana, n. sp. : a, zone-spicule, viewed from above, as 

 seen in situ ; b, the same, lateral view (observe the extremely 

 short shaft) ; c, body-spicule ; d, acerate flesh-spicule and stel- 

 late (Sc. D) ; e, more magnified view of the same. 



Fig. 44. T. penetrans, n. sp. : a, body-spicule ; b, acerate flesk-spicule 

 and stellate (Sc. A) ; c, more magnified view of stellate (Sc. 

 C) ; d, still more magnified view of ray of same. 



Fig. 45. Corallistes actdeata, n. sp. Oblique view of surface, showing 

 spikes (Sc. about A) : a, spike-spicule, lateral view ; b, base of 

 the spike, broken off, viewed from above (Sc. B). (Diagrams.) 



Fig. 46. C. verrucosa, n. sp. Oblique view of surface, showing verrucous 

 cones (Sc. about A) : a, verrucous cone-spicule, lateral view ; 

 b, base of the cone, viewed from above (Sc. B). (Diagrams.) 



Fig. 47. C. clegantissima, n. sp., spicule of (sc. l-48th to l-6000th). 



Plate VHI. 



Fig. 48. Discodermia papillata, n. sp. Portion of surface viewed from 

 above : a, disks covered with minute, fusiform, bacillar flesh- 

 spicules; b, the same without the flesh-spicule; c, subjacent 

 spiculation (Sc. about D) ; d, five figures to show the transfor- 

 mation into the surface-spiculation seen at c ; e, shaft of disk ; 

 /, papilla? on disk ; g, fully formed papillae, more magnified ; 

 h, fusiform bacillar flesh-spicule, much magnified ; i, ultimate 

 form of spicule of the interior ; k k k, interlocking of the ends 

 of the branches with those of neighbouring spicules ; /, cha- 

 racteristic form of " interlocking," much magnified. (Dia- 

 grams.) 



Fig. 49. D. aspera, n. sp. Portion of surface viewed from above : 

 a, disks covered with minute, acerate, curved, fusiform flesh- 

 spicules ; b, the same without the flesh-spicule (Sc. about D) ; 

 c, more magnified view of disk, showing denticulated margin 

 and papillae ; d, acerate flesh-spicule (Sc. D) ; e, the same, more 

 magnified ; /, more advanced form of disk, in which the papilla? 

 are transformed into spines, more or less divided ; g, four dia- 

 grams, showing the transformation of the papilla? into the 

 spinous condition ; h, ultimate form of spicule of the interior ; 



