I04 TABULATE CORALS. 



and T. elegantula, Bill.) exhibit the additional peculiarity that 

 the remote calices are upon the whole distributed in a small 

 number of vertical rows. Not only is there no true ccenen- 

 chyma in Trachypora, but the propriety of the step taken 

 by Dr Rominger in placing the genus among the Favositidce 

 is further shown conclusively by the fact that the cavities 

 of contiguous tubes are placed in communication by means 

 of a system of mural pores the importance of this fact not 

 being diminished by the comparatively small number of these 

 openings. It should be added that in some forms (including 

 the type-species, T. Davidsoni] such apertures in the walls of 

 the corallites have not yet been recognised ; but it may be 

 confidently expected that these structures will yet be brought 

 to light by a sufficiently minute examination. Lastly, Milne- 

 Edwards and Haime state that, in T. Davidsoni, "on ne dis- 

 tingue pas de cloisons ; " and the same statement will apply to 

 T. elegantula, Bill. In other cases, however, and especially in 

 T. ornata, Rom., the septa are quite recognisable as a well- 

 developed series of spines arranged in vertical rows. 



While I am unable at present to recognise any true relation- 

 ship between Seriatopora and Trachypora, I ought to add that 

 I have had no opportunity of examining microscopic sections 

 of the former, and that my conclusions are therefore based 

 upon the published descriptions and figures of Seriatopora. 

 There is a close general resemblance between such forms of 

 Trachypora as T. elegantula. Bill., on the one hand, and certain 

 forms of Seriatopora (e. g., Seriatopora elegans, Hist. Nat. des 

 Coralliaires, PI. F 4, figs. 3 a, 3 b) on the other hand ; and 

 it is possible that a microscopic examination of the latter may 

 show that this resemblance is based upon a real identity of 

 structure. All that I can affirm is, that the species of Trachy- 

 pora assuredly do not possess either a proper coenenchyma or 

 a columella, organs which are said to be present in Seriatopora, 

 and that there is thus established a wide difference in syste- 

 matic position. In the same way there is a striking resem- 

 blance between Trachypora ornata, Rom., and the living Pocil- 



