Sponges from South Australia. 505 



cytium ;" but, entertaining a different view of their nature, 1 

 must refer the student for my explanation of this assumption 

 to the 'Annals' of 1884, vol. xiv. pp. 20 and 21. The 

 species is very like Schmidt's Nardoa reticulum (Spong. 

 Kiiste V. Algier, p. 28, Taf. v. figs. 7 and 8). 



3. Glathrina tripodifera. 



Conical, rather compressed, sessile, fixed, with cloaca and 

 wide mouth ; or ovoid and free, with cloacal cavity, but no 

 mouth, that isHackel's "Auloplegma"-form. Texture delicate. 

 Colour of the former pinkish brown (? derived from having 

 been in proximity with a similarly coloured sponge) ; that 

 of the other specimens whitish grey. Surface even, uniformly 

 presenting a ridged quasi fibro-reticulated structure whose 

 interstices are more or less triangular, owing to the sigmoid 

 flexure of the ridges, which thus resemble a " plaited frill." 

 Pores in the ridges. Vents of two sizes, viz. small and large : 

 1, small, numerous, situated in the bends or interstices of the 

 sigmoid ridges, about l-96th in. in diameter ; 2, large, about 

 l-48th in. in diameter, scantily and irregularly scattered over 

 the surface ; both on a level with it, and both irregular in 

 their outline, which is unmarginated, and all leading into the 

 intervals between the echinated tubulation, which intervals 

 are shut off from the cloaca by the lining membrane of 

 the latter, as will be more particularly mentioned hereafter. 

 This applies to all the forms, both open and closed, while in 

 the " open " there is, of course, the addition of the vent or mouth 

 to the cloaca, which is smooth and naked, and the cloaca -in 

 all presents a blistered-like surface, rendered uneven by a 

 great number of infundibular depressions irregularly scattered 

 over it ; echinated throughout with the fourth ray of radiate 

 spicules, and in direct communication at the bottoms of the 

 " infundibular depressions " with the echinated tubulation 

 of the general structure ; also here and there with the 

 " intervals " between this tubulation, by a few subsidiary 

 apertures, which thus appear to be more accidental than 

 general. Structure massive, tubular ; tubulation subcir- 

 cular, averaging l-48th to l-72nd in. in diameter, composed 

 of a single layer of radiate spicules held together by sar- 

 code, supporting the other soft parts, extending almost 

 directly, that is being scantily branched, from the cloaca to 

 the surface, leaving the '^intervals" before mentioned between, 

 which are very irregular in form, and for the most part much 

 wider. Tubes densely and strikingly echinated with the 

 fourth ray of quadriradiates, whose curve is directed ^?^wards ; 

 while the other rays, imbedded in the sarcode, go to form the 



Ann. & Mag. N. Hist. Ser. 5. Vol. xvii. 35 



