tlie Genus Stenopora, Lonsdale. 177 



admit, however, that it' tliis be their real nature they differ in 

 some inexplicable points from ordinary perforated tabulge. In 

 Stenopora Hoiosii^ Nich, (' Annals,' Nov. 1883, p. 285), 

 the tabulai are not only perforated by central apertures, but 

 this fact is quite as easily recognizable in long sections as in 

 tangential ones. In this form, however, the tabulae are 

 extremely numerous, and the state of preservation is also 

 very good. Mr. John Young has proposed (' Annals,' Sept. 

 1883, p. 154) the generic name of Tahulipora for a coral 

 allied to or identical with Stenopora Howsii. In all other 

 respects^ however, save as regards its perforated tabulse, 

 8. Howsii does not differ from the normal species of 

 Stenopora. If no other species of Stenopora possessed 

 perforated tabulfB, there would be ground for accepting 

 Tahulijjora as a subgenus of Stenopora, or perhaps as a dis- 

 tinct genus. If, on the other hand, the structures above 

 described as occurring in S. australis are really perforated 

 tabulai, there does not seem to be any need for a special 

 generic name. Moreover, it is only on the supposition that 

 perforated tabula occur in the species of Stenopora generally 

 that we can account for Lonsdale's assertion that the mouths 

 of the corallites in this genus are " closed at the final period 

 of growth." In most of the specimens we have examined 

 (except S. Howsii) the surface is so badly preserved tliat the 

 characters of the mouths of the tubes could not be accurately 

 determined ; and in some (such as S. ovata, Lonsd.) , where 

 the preservation of the surface was better, we have not been 

 able to recognize any such closure of the mouths of the tubes*. 

 In one of the figures, however, which Lonsdale gives of S. 

 tasmaniensis (Phys. Descript. N. S. Wales, pi. viii. fig. 2^), 

 the structure in question is well shown, and it corresponds 

 entirely with what is seen in portions of the surface of S. 

 Howsii, where it is undoubtedly the result of the existence of 

 perforated tabulae. We have ourselves observed the same 

 structure in a single specimen of S. tasmaniensis, and we give 

 a figure of it here (PI. III. fig 11). We are therefore dis- 

 posed to believe that perforated tabulse were generally, if not 

 always, present in the species of Stenopora, but that they 

 were only produced (except in S. Hoivsii) at the final period 

 of the growth of the tubes, and that they were, with the above 

 exception, very few in number. It should be borne in mind 

 in this connexion that the state of preservation of almost all 

 the Australian and Tasmanian specimens of Stenopora which 

 have been examined by us is highly peculiar. They are not 



• Lonsdale himself states that he failed to recoguize the phenomenon 

 here alluded to in the case of S. ovafa. 



