H. B. KiKK. — On Neic Zealand Si^onges. Ill 



The scheme of classification followed in dealing with the 

 Calcarea will be generally that adopted by Dr. Dendy in his 

 " Monograph of the Victorian Sponges," part i., and his 

 " Synopsis of the Australian Calcarea Heterocoola." 



The present paper contains the descriptions of two simple 

 ascons, one of which I believe to be new. 



Phylum — Porifcra, Parazoa, or Spongics. 



Class — Calcarea (Grant). — Sponges in which the skeleton is 

 composed of calcareous spicules. 



Order — Homoccela (Polejaeft).— Calcarea in which the endo- 

 derm consists throughout of collared cells. 



Section I. — Hovioccela simplicia (Dendy). — " Homocosla in 

 which the ascon persons either remain solitary and do not 

 form colonies, or in which they form simple colonies in 

 which the component ascon persons may branch but never 

 form complex anastomoses nor give off radial tubes, so 

 that the individuality of the different members of the 

 colony is easily recognisable." 



Genus — Leucosolenia (Bowerbank). — Of the characters of the 

 order. 



1. Leucosolenia echinata, sp. nov. 



The sponge forms colonies of ascon persons springing from 

 a hollow, creeping, and anastomosing sponghoriza. The ascon 

 persons are cylindrical, and are generally wider than the 

 sponghoriza. They are usually about 6-5mm. in height and 

 may be as much as l-5mm. in diameter. Each tube has a 

 terminal osculum. The colour of the sponge is brownish- 

 white. 



The skeleton consists of triradiate, quadriradiate, and oxeote 

 spicules. The radiates are arranged in a single hiyer in the 

 mesoderm, the apical rays of the quadriradiates projecting 

 into the gastral cavity. The thicker end of the oxeotes is 

 embedded in the mesoderm, and the thin portion projects out- 

 wards and generally upwards through the ectoderm. 



S2ncules. 



Triradiates (PI. XXII., fig. Id) : These are generally regu- 

 lar, but are frequently slightly sagittal, in which case the oral 

 angle is the largest and the basal ray the longest. The ordi- 

 nary length of the rays is 0-lmm., but the basal ray may be 

 0-13mm. long. The thickness of the rays at the base is gene- 

 rally 0-Olmm., and they taper to a point. 



Quadriradiates (PL XXII., fig. Ic) : These are more nume- 

 rous than the triradiates, and larger. They are sagittal, the 

 oval angle being the largest and the basal ray the longest ; the 

 oral angle may be as great as 180°. The points of the oral 

 rays may be curved tow^ards each other in their own plane or 

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