322 Mr. H. J. Carter on the Strom atoporidse. 



allow of our identifying any other strueture with it, I cannot 

 admit that the animal which produced Stromatojyorcij whatever 

 it may have been, can have been a Spongozoon of the pre- 

 sent day or of any other period. If modified, it could not 

 have been a Spongozoon ! The minute branches of the vessels 

 of Str omatopor a mo^cvXdiiQ, to form the hydrophyton, while the 

 minute branches of the vessels of the excretory canal-system 

 of a Sponge commence in the ampullaceous sa,c {Wtmperkorbe). 



In the ' Annals ' for July this year, Dr. Dawson, F.R.S. 

 &c., shows himself, it is hoped, to be a much better geologist 

 than a palaeontologist ; for throughout his " careful micro- 

 scropic studies of Stromatojjorce " in 1878, he seems to have 

 been entirely ignorant of what Baron Rosen had done in 1867, 

 or he would surely have somewhere alluded to this remarkable 

 contribution to our knowledge of the Stromatoporidae. 



With such an omission, his failing to find the affinities of 

 Millejyora alcicomis to Stromatopora pointed out by " Mr. 

 Carter " is not surprising to me. 



To what " typical Stromatojiorce " of Hall, Nicholson, and 

 Winchell, Dr. Dawson alludes when it is implied, from the 

 statement in his 4th paragraph, " that the stelliform or 

 radiating canals do not occur in the common species of 8tro- 

 matopora^^'' I am ignorant ; for in all those to which I have 

 alluded as having been brought from America they are pre- 

 sent ; and Hall's Stromatopora constellata, as may be seen from 

 the illustration (op. cit. p. 324, pi. 72), seems to have been so 

 named from their presence. It is true that Hall makes this a 

 distinguishing character between his S. constellata and S. con- 

 centrica ; but, from what has been above stated, he might have 

 overlooked their representatives in the latter, as it is difficult 

 to conceive how a Stromatojjora could have been produced 

 without such an organization. 



Here, however, I would add that all the specimens of the 

 so-called Stromatoj)ora concentrica from the Upper Silurian 

 system which I have had in my own possession and have seen 

 in the museums of London, with the exception of one, have 

 presented the structure of /S'. concentrica above detailed ; but 

 this one, which is the type sioecimen from which Lonsdale took 

 his description and delineated his figure in Murchison's ' Silu- 

 rian System ' (1839), does not present the characters of 8tro- 

 matoporttj in so far as the surface, although covered with mi- 

 nute granulation, possesses no stelliform groups of vessels 

 and nothing else besides the miliary granulation ; while 

 the vertical section, shows an amount of regularity in the 

 laminre which is seldom seen in the Strovnatopora^^ together 

 with a form of chamber or interstice square below and arched 

 above, totally different from that of the Stromatoporce^ which, 



