1130 A .MONOGRAPH OF THE AUSTRALIAN SPONGES, 



dinal direction, parallel to the longitudinal axis of the body, but 

 pointing a little outwards with the oral end. They are situated 

 in several parallel laye:s closely backed (10 to 15 layers at the 

 thickest place in the body-wall). The small interstice between 

 the Acerates are filled up by small Triradiates, which surround 

 sheath-like the inner Acerates. Most of them are sagittal and 

 are with their basal ray parallel to the longitudinal axis of the 

 body, whilst both the lateral rays diverge to the oral side, and 

 often embrace the acerate spicules by their more or less curvity. 

 The unpaired angle 150° to 170°, both the paired ones 95 to 105°. 

 The straight basal ray measures 015 to 2 in length. Their 

 basal thickness 0-005 to 0-008 mm. Between the sagittal rays 

 there are also single irregular, rarely regular triradiate spicules. 

 The sagittal quadriradiate spicules which coat the whole inner 

 surface of the G-astral cavity, and the larger canals, and which 

 are arranged regularly, the basal ray towards the aboral side, 

 possess an unpaired angle of 160 to 170°, the two paired angles 

 100 to 95°. Their basal ray is to 0*35 mm., long, straight, their 

 slightly curved lateral rays 0-2 to 0'3 mm., and like the basal ray 

 only 0005 mm., thick. But the apical ray is 2 to 6 times thicker, 

 that is 0-01 — 0-02 or 003 mm., in thickness. It is very varying, 

 in the greater part of the Grastral cavity only 0*1 — 15, but 

 towards the Osculum 3 — 0"4 mm., long. The entrance to the 

 Gastral cavity is in this way hindered by a terrible circle of strong 

 apical rays just below the Osculum. 



Locality : East Coast of Australia, Port Jackson, Frauenfeld ; 

 Port Denison, Von Lendenfeld. 



44. SPECIES. LEUCANDRA TYPICA. Von Lendenfeld. 

 LEUCONIA TYPICA. var. tuba. N. PoMjaeff (1.) 



This Sponge attains a length of 40 mm. and an average 

 diameter of 12 mm., the thickness of the body wall is 3 mm. 

 The round flagellated chambers in this species have particularly 

 regular outlines, and are smaller than in any other case, their 

 diameter rarely exceeding 0*04 mm. 



( 1 . ) N. PoUjaeff. Report on the Calearea. The Zoology of the Voyage 

 of H.M.S. Challenger. Part XXIV., p. 56, pi. VII., figs, 2a-2c. 



