SPONGES FROM THE MERGUI ARCHIPELAGO. 



81 



Hab. Growing on hard objects. 

 Loc. King Island- 

 er bs. The black colour together with the presence of a circum- 

 ferential line of zone-spicules distinguishes this species from 

 Tetliya cranium and its foregoing variety, viz. var. robusta, 

 although in its general structure it is like the latter. As far 

 back as 1869 (Ann. & Mag. Nat. Hist. vol. iv. p. 4) I noticed the 

 presence of an isolated patch of zone-spicules in the circumference 

 of Tetliya arabica, and afterwards observed them in a small speci- 

 men from the tropics, mounted on a card in the British Museum 

 (No. 452). In these cases they differed from those above described 

 in the possession of a longer shaft and shorter arms (ojp. cit. 1883, 

 xi. pi. xv. fig. 9), thus resembling the zone-spicule of G-eodia. 

 Sometimes the bihamate flesh-spicule is wanting in these sponge?, 

 but I only know of one instance of this, viz. in Tethya antarctica, 

 Carter. Very often the heads of the anchor-spicules outside 

 appear to be absent when they really were not during life, for 

 they are so delicate that the least contact of their arms with any 

 opposing object will break them off, and thus their absence may 

 lead to the conclusion that they never existed. 



The reticulate fibro-dermal structure covered by a layer of 

 sarcode rendered cribriform by the pores, and more strikingly 

 marked by being densely charged with the dark pigmental cells 

 and flesh-spicules, recalls to mind that which is so characteristic 

 of the dermal structure in Thenea JVallichii, just below the 

 pileus or hat-like upper portion of this sponge. There is only 

 one specimen of Tethya merguiensis in Dr. Anderson's collection. 



GrEKERAL OBSERVATIONS. 



On referring to the table at the commencement of this Report 

 it will be observed that the collection consists of 89 specimens, 

 referred to 38 species, 13 of which, including representatives of 

 one new genus, have not been made known before, 9 are new 

 varieties, and the rest have already been named and described. 

 Most of the sponges have been examined and characterized in 

 the dried state by preference, although the greater part arrived 

 in spirit. 



In estimating the sponge-productiveness of a locality, and, 

 indeed, its fauna and flora generally, the number of species should 



