West- 1 III liaii S^ec/e.-* (?/* Madrepora. 31 



8. No. 112. 6. 8. 214. Tliui-sil;iy Isluiul. Savlllc K'jiit 

 collection. 



Tliis is the last specimen in Brook's list, and it is tli!it 

 which most closely resembles M. ccroiconiis. It agrees with 

 that form in (1) the radial corallites being narifonn below 

 and tubo-naritbrm in the distal parts, (2) in the thin walls of 

 the terminal radial corallite, and (3) in the striate or echinu- 

 late ornamentation of the walls of the corallites. 



These three characters are common to most of the arbo- 

 rescent Madrepores ; the first and third characters occiur in 

 nearly all, as, e. g.^ in M. interincdia. Tlie most important 

 ])oint of resemblance between this specimen and M. ceroi- 

 coriuH is the length of the terminal corallite. This structure 

 is shown, however, only on one branch of the Tliursiay Island 

 specimen. 



There are not wanting differences between this coral an 1 

 Brook's de3crij)tion of J/, cervicornis. Thus he states that 

 the primary septa are subequal, whereas in this specimen they 

 are very unequal, while the one terminal corallite, though of 

 the same length as in M. cervicornis, is narrower, bsing 

 3 millim. instead of 4-5 millim. in diameter. 



Why this specimen, with its long narrow terminal corallite, 

 was regarded as the same species and variety as the Port 

 Darwin specimens, with their short, broad, thick-wallei, 

 terminal corallites, is not obvious. 



Hence I am driven to the conclusion that the evidence of 

 the eight Madrepores which Brook catalogued as Indo-Pacific 

 representatives of M. palmata, cervicornis, and proli/era is 

 insufficient to prove the occurrence of those species in the 

 Indo-Pacific Ocean. 



Summary of Conclusions. 



1. M. pahnatn, Lam., may be conveniently kejit distinct 



from M. cervicornisj since [a) the two forms live urifler 

 identical conditions, their diflferences are not due to 

 environment, and {h) the evidence of the intermediate 

 forms is inconclusive. 



2. M. pcilnKtfd, Lam,, shoidd not be treated as the typical 



form of J/, muricata, L., from which Linnieus ex- 

 cluded it. 



'.\. If the name .1/. niuricata be retained, which seems un- 

 desirable, it should be used for an Indo-Pacific species. 



4. The evidence of the range of M. pdhnnta^ }f. cervicornis^ 

 and M. proli/era into the Indo-Pacific is inadequate. 



