sroNGiiDA. 457 



each end ; size # 19 by *0079 to -25 by -0095 millim. (3) Echinating 

 spined cylindrical ; base with slight globular inflation ; tapering 

 gradually to blunt distal end ; spines short (the longest about '0016 

 rnilliin. long), thorn-like, sharp, shortest at apex, those of distal 

 half more or less recurvate towards base, distributed equally over 

 whole of spicule; size of spicule -uiJ5 to '100 by "01 millim. (apex 

 of spicule about *o05 millim. thick). 



Hub. Thursday Island, Torres Straits, 4-5 fms. ; bottom sand. 



A single dry specimen, 70 millim. (2| inches) high by 60 millim. 

 (2| inches) in greatest width. The arborescent growth distin- 

 guishes it at once from the turbinate E. bilamellatum, vasiplicatum, 

 and costiferum, and the palmate, branched E. nervosum, mihi 

 (Lamarck), the only species hitherto recognized ; in fibre-structure it 

 closely resembles E. bilamellatum, although the spicules are some- 

 what smaller. The much smaller smooth acuate and acerate distin- 

 guishes it from E. laciniatum anipyJcei. 



Echinodictyuni glomeratum, var. subglobosum. 



Two dry specimens, consisting of an obsolescent stem, rising at 

 once into a globular clathrous or honeycombed head, formed by 

 rapid branching at subacute angles and free anastomosis ; the 

 branches appear to end bluntly on the surface in rough points, at 

 about the same level (this, however, is perhaps partly due to abra- 

 sion on the shore). Texture rigid, harsh ; colour pale brown in 

 macerated, dark purplish in non-macerated specimen. Spicules : — 

 (1) Long setaceous acuate, with well-rounded head, tapering to sharp 

 point ; size about 2*0 by "00127 millim. : apparently echinating the 

 bases of the primary fibres. (2) Smooth acerate of fibre, slightly 

 curved, tapering gradually to sharp points ; size "25 by -0085 millim. 

 to -33 by -0127 millim. (3) Spined echinating cylindrical, with 

 slightly indicated head and apex almost coming to a point ; spines 

 numerous, fine, sharp, straight at middle, recurvate at distal end of 

 spicule ; size -106 to -16 by -0085 to -0095 millim. Skeleton-fibres 

 stout, compact, almost straight, sometimes with yellow transparent 

 margins ; secondary fibres given off at right, or more usually acute, 

 angles from primaries. 



Hub. Torres Straits, 5-10 fms. ; bottom sand and coral. 



A well-marked variety. The outward form and the almost pointed 

 spined spicule distinguish this from the typical form. One specimen 

 measures 40 millim., the other 75 millim. (3 inches) in both 

 greatest height and diameter. 



86. Echinodictyum cancellatum. (Plate XL. fig. D ; 

 Plate XLII. fig. q.) 



? Spongia cancellata, Lamarck, Ann. Mus. Hist. Nat. xx. p. 456. 



The short description of Lamarck agrees so closely, so far as it 

 goes, with the external character of this sponge, that in default of 

 information as to the minute characters of the old species, I assign 



