TETHTOEEHAPHIS. 55 



the sponge ; more abundant in the surface and the walls of the inhalant 

 canals, measuring 0-014 x 0*003 millim., with irregular thickenings and 

 excrescences. 



Geographical Disteibution. — East coast of Australia: Port Jackson, 

 N. S. W. {Lendenfeld). 



Tethyorrhaphis conulosa, n. sp. 



Spherical sponges, 30-40 millim. in diameter, attached by a small base. 

 The surface is covered with high conical protuberances, on an average 

 6 millim. broad and 6 millim. high ; these are rather irregular at the base,, 

 and taper to sharp points. The conuli on the upper side of the sponge 

 have a more rounded apex, towards the base they become pointed, and those 

 which surround the base itself are prolonged to form thread-shaped rootlets,, 

 which may attain a length of 15 millim. Colour of the living sponge yellowish 

 red ; in spirit more dull. The lower surface of the cortex is quite smooth ; 

 its thickness accordingly subject to great variations. Below the depressions 

 the cortex is ouly 2 millim. thick ; while it attains a thickness of 8 millim. 

 and more below the high conuli. Tangential canals, 0-4 millim. wide, extend 

 below the surface of the depressions. Numerous narrow branched canals, 

 which are on an average 0"08 millim. wide, arise from these and extend 

 centripetally. In the pulpa the canals extend in a very irregular manner;, 

 their average diameter is 0'016 millim. 



Skeleton. — Eadial spicule-bundles 2 millim. apart and 0-5 millim. thick. — 

 (1) Monad Meyasclera. Strongyla, straight or curved, 2 x 0*04 millim., thickest 

 portion near the middle, spindle-shaped, blunter end about four times as 

 thick as the other. These spicules form the radial bundles. In the cortex, 

 between the surface-tufts, styli, measuring 0'5Gx 0-014 millim., and situated 

 oblique to the surface, are met with ; these are straight, the pointed end 

 looking outward. Neither these nor the distal buudle-spicules project beyond, 

 the surface. — (2) Stellate Microsclera. Of two kinds : — (A) Griobose Stellates with 

 conic sharp-pointed rays, measuring 0-07 millim. in diameter. These spicules 

 are found only in the outermost layer of the pnlpa. (B) Small Stellates with 

 slender cylijidrical rays, measuring 0*04 millim. in diameter, scattered irre- 

 gularly throughout the sponge.— (_3) Oxeote Microsclera. Very abundant, par- 

 ticularly in the cortex, where they are on an average only 0-024 millim. apart. 

 These spicules form a thin but very dense layer on the surface, and measure 

 0-018 X 0-003 millim. ; their shape is variable. Transition-forms between theso 

 and the stellates, variety B, are not rare. 



Geogeaphical Disthibution. — East coast of Australia: Port Jack-on, 

 N. S. AV. {Ramsay). 



