1902.] SPONGES OF THE " SKEAT EXPEDITION." 215 



Oxeas 0-94 x 0-04 to 0-35 x 0-03 mni. ; oxeas bent twice, 0*28 x 

 0*06 mm. 



Styles 0*70 xO'34 mm,, occasional. 



Still rarer are tornotes 0*88 x 0'032 and 0-56 x 0*02 mm. 



Both the stoutest and the slenderest spicules are confined to 

 the axis, 



Pulau Bidang. 



14, OlOCALYPTA RUTILA, n. sp, (Plate XIV, fig, 7,) 



Sponge small, 25 x 8 mm, ; very fiagile, transparent, of a 

 golden-bi'Own colour. 



Like that of C. melichlora just described, the structure is 

 that typical of the genus in its narrower sense (Ridley & Dendy, 

 Voj^age of H.M.S. ' Challenger,' vol. xx. p. 173). 



The axial cohimn is of very light build, spongy and cavernous. 

 The dermal membrane like that of C. hyaloderma (Ridley & 

 Dendy, loc. cit. p. 174) is marked w-ith little stars whei-e the 

 pillars of supporting spicules meet it. 



Oxeas, with a few styles, 0*98 x 0*02 mm. 



Pulau Bidang, 



15, Tethya ingalli Bowerb. 



Tethya ingalli SoUas, Yoyage of H,M.S. ' Challenger,' vol. xxv. 

 p. 431, pi, xliv. 



Sponge spherical, attached, sui-face even. Cortex fibrous 

 throughout, about 1 mm, thick, without intercortical cavities. 

 Pores leading into naiTow canals. Oscula similar to the pores. 



Megascleres: Strongyloxeas 1*76 x 0-035; 1 •40x0-03 mm.; 

 0-32 mm. ; slender, abundant. 



Microscleres : Spherasters 0-060-0-012 mm. Chiasters variable, 

 0-012 mm. Oxyasters 0-030-0-024 mm. 



Kirkpatrick (P. Z. S. 1900) compares the spicule measurements 

 of Christmas Island, Fremantle, and ' Challenger ' specimens 

 thus : — 



Strongyloxea. Spheraster. Chiaster. Oxyaster. 



Christmas 1 1-36x0-024 0-070 0-012 0-018-0-024 



Fremantle 1-47x0-035 0-070 0-012 0-036 



'Challenger' { 0-026-0^032 0-065-0-085 0-012-0-016 0-035-0-043 



to which we may add 



'Skeat' { 0-03^^035 0-060-0-012 0-012 0-024-0-030 



The specimen is gemmiferous, bearing several very young 

 gemmules and one comparatively advanced (8 mm. in diam.), sunk 

 in the parent tissues. In this gemmule microscleres resembling 

 those of the adult are absent, but a number of globules are 

 present — varying in size, the largest being 0-02 mm, in diameter. 

 The largest globules are thus a little smaller than the centrvim of 

 the largest spheraster of the adult, and I supposed that the 

 globule was the young stage of a spheraster. Since coming to 



