&42 Mb. j. s. 6.\bdineb. on coeals [Bee. 14, 



Family Poclllopoeid^. 

 I. Genus Pocillopoea, Lamarck. 



Pocillopora, Lamarck, Hist. Anim. sans A^ert, ii. p. 273. 



Pocillopora, Duncan, Rev. Madrep., Jour. Linn. Soc, Zool. 

 vol. xviii. p. 47. 



The classificatorv characters of the species in this genus by 

 means ot the corallum are extremely unsatisfactory. In the 

 collections there are over 50 specimens, either whole colonies or 

 branches from different colonies, and in addition I have examined 

 a very large number of specimens in the British Museum. These 

 show an almost complete series from P. acuta to P. madrepovacea ; 

 and any division into subgenera does not seem to me to be 

 admissible, nor do there appear to be any chai'acters running 

 through a limited number of species which wUl serve to di\ide up 

 the genus in anyway for classiticatoiy purposes. The examination 

 of the polyps in such widely separated species as P. snffruticosa, 

 P. favosa, and P. grandis has failed to show me any differences in 

 their macroscopic anatomy ; and I am doubtful whether all these 

 so-called species should not rather be described as varieties of 

 one species, the characters of which would be the characters of 

 the whole genus. 



The growth of the colony is much more vigorous toward the 

 summits of the branches, and to this is due the angular character 

 of the calices here and their very thin walls. The complete 

 absence of verrucse on the tops of the branches and their incrassate 

 form in such a species as P. grandis are due to the ends of the 

 branches having reached the low-tide level, and, being unable to 

 grow further upwards, increasing in boih thickness and breadth. 

 Although this is by far the most common species of Madreporaria 

 on the reef at Funafuti, I never found any of its branches with 

 their summits dead, even though they reach almost invariably to 

 the low-tide level. The colonies exhibit generally a very marked 

 growth towards the light, and the under surfaces of horizontally 

 growing branches of clumps are often completely bare of verrucae. 

 The living colonies are usually green or pink when the polyps 

 are expanded, but if retracted are nearly colourless. 



1. POCILLOPOBA PAUCISTELLATA, Quelch. 



Pocillopora pancistelkita, Quelch, Challenger Eeport on Eeef- 

 Corals, p. 6o, pi. i. figs. 3-3 a. 



A few small pieces were dredged which agree well with Quelch's 

 description. The corallum is rather more delicate and branched 

 than the tj^pe. The calices are surrounded by short spines, and 

 the primary septa are visible as spinulous projections in some 

 of the subterminal corallites. 



Funafuti ; 5 aud 7 fathoms. 



