SPONGES FROM THE ABROLHOS ISLANDS. 48i5 
they are arranged tangent ially. The rays of the large triradiates measure up 
to 1-1 by 0-23 mm., those of the smaller 0-18 by 0-013 mm. 
Previously Jcnoivn Distribution. Bermudas [Poldjaeff^ ; Australia {Polejaeff, 
Ridley, Lendenfeld, Dendy). 
Register No. and Locality. VI. 17 b, Sandy Isle. 
6. Leucaltis clathria Haeckel. 
(For literature and synonymy vide Dendy and Row [1913].) 
There are two very fine specimens of characteristic external form, each 
measuring about 80 mm. in diameter. 
Previously known Distribution. See Dendy [1913]. 
Register No. and Locality. III. 3, IV. 2, Wooded Isle. 
7. Sycon GELATINOSUM de Blainville. 
(For literature and synonyruy vide Dendy and Row [1913].) 
There are six specimens of this common Australian species in the collection, 
usually forming colonies of several or many persons, but varying considerably 
in the size of person and in the way in which the colony branches ; the 
largest person measures 25 mm. in height and 12 mm. in greatest diameter. 
The colour in spirit varies from light yellowish brown to dull greyish 
"brovifn. The oscula are all provided with a fringe of spicules. 
There is one specimen (R.N. VII. 1 d) consisting of a single person only ; 
it is 16 mm. in height and has an average diameter of 7 mm. ; the colour in 
spirit is almost white. 
The internal structure and spiculation of all the specimens are typical. 
Previously known Distribution. Australia (various authors and collections) ; 
Java [Haeckel). 
Register Nos. and Localities. II. 2, II. 5 a, III. 2, III. 13 a. III. 13 J, 
Wooded Isle ; VII. 1 d, Sandy Isle. . 
8. Vosmaeeopsis mackinnoni n. sp. (PI. 25. fig. 4 ; PI. 26- fig. 6.) 
Sponge (PI. 25. fig. 4) colonial, consisting of a number of short, thick, 
subcylindrical individuals uuited together in an irregular manner along a 
greater or lesser portion of their length. Each individual has a circular or 
oval osculum at its summit ; in perfect individuals a beautiful oscular fringe 
is present, formed of very long, hair-like oxea ; in others this fringe is broken 
off short. The individuals varj^ rather in size owing to their peculiar 
branching and colonial habit ; an average full-grown person is 15 mm. in 
height and 3 mm. in diameter, the thickness of the wall being 1'3 mm. The 
outer surface is rough and uneven, and large oxea can be seen projecting 
irreo'ularly from it ; these oxea are more or less absent from the basal portions 
of the sponge, where the surface is much more even and only slightly 
roughened. Colour in spirit pale brown ; texture rather fragile. 
35* 
