REPORT ON THE MONAXONIDA. 3 



size of the spicules. The following table shows the length of the largest spicules in 

 various specimens. 



1. A specimen from Ilfracombe, in the Bowerbank collection, Brit. Mus.; average 



maximum length about 0"35 mm. 



2. Mr. Carter's specimen from Kerguelen ; average maximum length about 0*5 mm. 



3. One of the Challenger specimens from Kerguelen ; average maximum length 



about 0'6 mm. 



4. Another of the Challenger specimens from Kerguelen ; average maximum length 



about 077 mm. 



5. Amorphina megalorhaphis (as given by Carter, loc. cit.), "varying in leno-th 



from l-128th to l-23rd inch" ( = about from 0-2 to 1-0 mm.). 



Under these circumstances we consider ourselves justified in including aU the above 

 mentioned specimens under the name " Halichondria j^anicea." 



Some of the Challenger specimens from Kerguelen are infested by a very 

 abundant Oscillatorian Alga ; especially one which is coloured of a dark chocolate 

 brown, but whether the colour is due to the Alga or not is an open question ; several 

 sponges from Kerguelen were similarly coloured. 



There is also a single small specimen, noteworthy on account of its dark coloration 

 at and near the surface, from a pool at Oosima, Japan ; this agrees in every essential 

 respect with the common British form ; the oscula are distinct and rather large, the 

 dermal skeleton beautifully reticulate, and the spicules up to about 0'5 by 0-0126 mm. 

 in size. 



The species thus appears to be cosmopolitan. 



Localities. — "Royal Sound, Kerguelen, 20-60 fathoms;" "Kerguelen, 10-100 

 fathoms;" "Christmas Harbour, Kerguelen, 60 fathoms;" Oosima, Japan, 14th March 

 1875, "Pool," one specimen. 



Habitat. — British Seas (Johnston, Bowerbank, &c.); Basse Rocks, ofi' south-east 

 coast of Ceylon (Carter); Kerguelen (Carter, Challenger); Torres Strait (Ridley, 

 "Alert"); Atlantic (Carter); Japan (Challenger). 



Halichondria caduca, Bowerbank (PI. II. fig. 15). 



1866, &c. Halichondria caduca, Bowerbank, Mon. Brit. Spong., vol. ii. p. 234, and vol. iii. 



pi. xU. figs. 9-11. 



We identify with this species a single small, cavernous specimen from off" the south- 

 west coast of Patagonia (Station uncertain). It agrees well with Bowerbank's species in 

 external form, colour, rugged surface and probably also in its cavernous structure ; also 

 in the size and form of the spicules (PI. II. fig. 15), which measure about 0'28 by O'Ol mm. 



