020 FUNAFUTI ATOLL. 



Microsclera (a) Minute slender isochelse; length about 0-015 

 mm. 



(b) Long slender toxa, with a short slight bend in the middle, 

 straight limbs, and smooth acute points ; length 35 mm. 

 *|This species forms a thin skin-like covering over an oyster 

 shell, Ostrcea crista-galli, Linn. 



Obtained in the lagoon in eighteen fathoms of water. 



AGELAS GEACILIS, sp. nov. 

 (Plate xviii., fig. 4). 



Sponge subcylindrical, unbranched, attached to fragments of 

 shells. There are four pieces, three of which take the form of 

 simple filaments measuring from 2 to 3 mm. in diameter, and 

 from 25 to 75 mm. in length. The fourth example consists of 

 six or seven processes arising from an expanded base ; at their 

 origin and for about half their length they are somewhat irregular, 

 a little flattened and joined together at various points, giving the 

 basal portion a clathrous aspect. The upper half terminates in a 

 series of subcylindrical filaments from 5 to 25 mm. in height and 

 2 mm. in diameter, which taper gradually to the extremities. 



The texture is spongy and soft, but pretty tough. Colour in 

 spirits grayish-yellow. The surface is uneven, hispid, beset with 

 numerous minute conuli from 0-2 to 0-5 mm. high and 2 to 5 mm. 

 apart. "p A few minute pores are visible between the conuli. 



The skeleton is reticulate, the stout primary fibres forming an 

 axial plexus from which secondary and connecting fibres are given 

 off. The mesh is oblong or oval, rarely angular. The primary 

 fibres measure 0'07 mm., the secondaries 0*045 mm., and the 

 connecting fibres 0-025 mm. 



The echinating spicules situated on the main fibres are numerous 

 and generally more or less parallel with them, on the more slender 

 fibres they are usually at right angles to their support. 



Megasclera Of one kind only, consisting of straight or but 

 little curved, verticillately spined styli, from the truncated 

 base they taper gradually to sharp points. The verticils vary in 

 number from 16 to 24, according to the size of the spicule. The 

 first three or four" are closer than the rest, and consist of prominent 

 straight spines, towards the apex the spines are recurved. 



Size Variable from 0-1 to 0*22 mm. by 0-007 to 0013 mm. 

 The verticils are about 0-01 mm. apart. 



Obtained by tangles, associated with Gorgonice, in forty to 

 seventy fathoms, on the western slope of the atoll. 



ECHINODICTIUM ASPERUM, Ridley & Dendy. 



Echinodictium asperurn, Ridley & Dendy, Chall. Rep. Zool., xx., 

 p. 165, pi. xxxii., fig. 2. 



