198 FUNAFUTI ATOLL. 



that an individual might exhibit each variation as circumstances 

 altered. He writes as follows* : 



" This species varies in a remarkable manner in the extent of 

 the spines over the body : sometimes they project much out of 

 the skin, and cover nearly the entire body like bristles : some- 

 times they are much less numerous, and nearly entirely hidden in 

 the skin, the greater part of which appears to be smooth." 



Tetrodon nigropunctatus is included in a division characterised 

 by the presence on each side of the snout of " two solid nasal 

 tentacles without opening." Of this species I would rather say 

 that there is a single tentacle on each side of the snout, each 

 tentacle consisting of a stalk separated at about half its height 

 into two lobes. On examining these lobes with a lens they were 

 seen to be distinctly porous at the apex, and suspecting the 

 presence of a canal one of the tentacles was removed, when two 

 depressions were observable in the pedicle, each depression cor- 

 responding with one of the lobes. On cutting sections, the 

 microscope revealed the presence of two black spots which may 

 have been the pigmental and juxtaposed walls of two canals. 

 The tentacles had however been so shrivelled, that nothing more 

 satisfactory could be made out. 



The native name of the species, which is very common around 

 the Atoll, is " Soui." 



TETRODON IMMACULATUS, Block. 



Tetrodon immaculatus, Bloch., Schn., p. 507 ; Bleeker, Atlas 

 Ichth., p. 75, pi. ccxi., fig. 1, 



One half-grown example is included in the Collection. The 

 stomachs of all these Tetrodons were crowded with coral, which 

 grated together when the body was touched. In T. nigro- 

 punctatus the coral consisted of the finer branchlets of a 

 Pocillopora, found growing in the shallower water where the 

 Tetrodons were obtained. Some of the pieces swallowed, measured 

 nearly f inch in length, and were much branched. 



The food of T. immaculatus, as exhibited by our specimen, was 

 composed of pieces of the stock of a coral unbranched, and not 

 exceeding a pea in size. With these were associated some Fora- 

 minifera, which my colleague, Mr. Thomas Whitelegge, has 

 identified as Orbitolites complanata and Tinoporus baculatus. 



Darwin has noticed two species of Scarus as browsing upon 

 corals, f 



*GHinther Cat. of Fishes, viii., p. 293. 

 t Darwin Coral Eeefs, 1874, p. 19. 



