Sponge-fauna of Madras. 157 



oank's species, however, grows to a far greater size and differs 

 widelj enough in the arrangement of the oscula on the upper 

 surface and in the smaller size of the tylote spicules. 



The most remarkable feature about 8. inconstans is its 

 extreme variability in external form ; it thus affords a striking 

 parallel to the cases of Sprnosella sororia and PachycJialina 

 variabilis, two common West-Indian Chalinine sponges, with 

 which I have dealt at length elsewhere *. 



Halichondria panicea, Johnston, var. 

 1842. Halichondria panicea, Jolinston, British Sponges, p. 114. 



I identify with this well-known and widely-distributed 

 species a single massive specimen measuring about 100 millim. 

 in average diameter, with a well-marked tendency to give off 

 above short, digitate, tubular processes. Surface covered with 

 small monticular prominences. Colour (dry) white below 

 and light pink above. Texture very soft and crumbling. 



Both the main and dermal skeletons form a very confused, 

 irregular, and loosely put together reticulation of spicules, 

 apparently with no spongin. 



The spicules are the usual slightly curved, long, gradually 

 sharp-pointed, fusiform oxea; they average about 0*7 by 

 0"014 millim. in size when full-grown, thus agreeing fairly 

 well with those of the Kerguelen variety. 



Mr. Carter f has already recorded a sponge which he calls 

 " Amorjyhina megalorkaphis, n. sp.," from Ceylon, and he 

 also remarks, in the same place : " This seems to be a 

 variety of the common British species Halichondria panicea, 

 chiefly differentiated by the size of its largest spicules, which 

 is double that of the English one." 



The synonymy and geographical distribution of the species 

 will be found in the Report on the Monaxonida dredged by 

 H.M.S. ' Challenger,' p. 2. 



Tedania digitata, Schmidt, sp. 

 1862. Reniera digitata, Sclimidt, Spong. adriat. Meeres, p. 75. 



There is one fine specimen which is undoubtedly referable 

 to this widely distributed species. It consists of a low- 

 growing mass rising up into short, digitate, conical processes 

 or large mamillge, and has a very uneven, corrugated surface. 

 In its present (dry) condition it is of a pale yellow colour 

 tinged with pink, but a label with it states that the colour, 

 when alive, was red. 



The measurements of the spicules are as follows : — Smooth 

 * Proc. Zool. Soc. 1887. 

 t Ann. & Mag. Nat. Hist. ser. 5, vol. vii. p. 868. 



