624 COLLECTIONS FROM THE WESTERN TNDIAN OCEAN. 



lower part of sponge glabrous. Consistence is spirit very tough, 

 elastic ; colour dull olivaceous brown. 



Main skeleton rather loose, formed of broad tracts of loosely 

 aggregated spicules, horizontally or obliquely arranged with regard 

 to the surface, aud of intercrossing spicules loosely scattered between 

 them ; that of the cortex, which forms a denser layer, consists of 

 more compact bundles, 10 to 15 spicules broad, placed vertically 

 with regard to the surface, from which their points project; the 

 bundles are from "1 to -14 millim. apart. Sarcode subtransparent, 

 bright greenish brown, crowded with globular cells about -Oil millim. 

 broad, with large nucleus and one or more opaque granules. 



Spicules : — (1) Skeleton spinulate, smooth, straight or slightly 

 curved ; head oval, longitudinally elongate, slightly flattened at free 

 end, of about same diameter as middle of shaft, tapering gradually 

 from centre of shaft to sharp apex ; size of spicule # 4 by '013 millim. 

 (2) Spinispirular, short, slender, consisting of about four bends, 

 about 6 spines to a bend ; spines sharp, about - 002 millim. long ; 

 size of spicule # 02 by -002 millim. (exclusive of spines). 



Hah. Mozambique, between tide-marks. 



Distribution. Mauritius (Carter). 



The greatest height of the single spirit-specimen representing this 

 species is 65 millim. (2| inches), the greatest diameter 25 millim. ; 

 its form is that of a much drawn-out, truncate cone, compressed so 

 that the loug diameter is about twice that of the small one ; there 

 is a nodular process, 5 millim. high, on one side near the extremity ; 

 the base includes a large amount of coarse foreign bodies. The 

 characters agree well with those given by Mr. Carter (I. e.) for a 

 fragment from Mauritius. It is nearly related to Hymeniaeidon 

 angulata of Bowerbank (Madeira), and vagabunda and decumbens, 

 mihi (Australia, this Report, Part I. pp. 46S, 470) ; but it is dis- 

 tinguished readily from all by its very short spinispirular spicule. 



48. Tethya cliftoni. 



Tethea cliftoni, Bowerbank, P. Z. S. 1873, p. 16, pi. iii. figs. 14-18. 



A single specimen, cream -white, covered with low papilla; about 

 1*5 millim. in diameter. The species, unless the separation of the 

 large stellates into two distinct dermal zones proves to be constant and 

 distinctive, can hardly be kept distinct from T. ingalli (Freemantle, 

 Australia) and T. robusta (Australia), both of Bowerbank, the chief 

 difference being in the diameter of the acuate, which in T. cliftoni is 

 about "025 millim., in T. ingalli "035 millim., and in T. robusta '045 

 millim. Again, all three species are scarcely more than varietally 

 distinct from T. lyncurium of Europe, differing from it mainly in 

 the greater distinctness of the heads of the small stellates. 



Hah. Seychelle Islands, 12 fms. 



Distribution. S.W. Australia (Bowerbank). 



