572 SYDNEY J. HIOKSON. 



Syringopora is examined with spines in this rudimentary con- 

 dition and compared with a specimen of Tubipora, no difference 

 of importance can be distinguished between the two genera in 

 this respect. 



These, then, are the three principal objections to the rela- 

 tionship between Tubipora and Syringopora, and, as I have 

 endeavoured to show, none of them is by any means insuperable. 

 When this is borne in mind, and the numerous points con- 

 sidered in which the two genera resemble one another, I think 

 that the Zoantharian affinities of Syringopora must at least be 

 considered very doubtful. 



The corallum in both Syringopora and Tubipora consists of 

 a number of tubular parallel corallites separated from one 

 another by spaces, which are bridged over by hollow tubular 

 processes in Syringopora or platforms containing a network of 

 canals in Tubipora. In both genera new buds are formed on 

 these connections between the corallites, a striking similarity 

 which has been quite recently dwelt upon by G. von Koch 

 (10a), in a paper which came into my hands since my plates 

 were sent to the lithographer. 



I have drawn in fig. 13 « a corallite springing from one of 

 the tubular connections between the corallites in Syringopora, 

 and if this be compared with the corallites springing from the 

 platforms in fig. 1 a, or in von Koch's fig. 20, the striking 

 similarity between the two genera in this respect will be 

 seen. 



When the surface of a corallite of Syringopora is examined 

 with a lens it is seen to be covered with a number of small pits 

 which bear a striking resemblance to the mouths of the per- 

 forations of Tubipora (fig. 2, h h), and this pitting can be seen 

 quite as plainly and distinctly on the inner side as on the 

 outer side of the corallites. Although these pits do not pene- 

 trate the walls in Syringopora as this coral is presented to us 

 after centuries of fossilisation, yet I think they ajQFord some 

 confirmation of the o])inion that itt; corallites are really of the 

 same nature, i. e. spicular, as in Tubipora. This opinion is, 

 moreover, still further confirmed by an examination of the 



