Prof. P. M. Duncnn on the Genus Hindia. 263 



from the same strata, in the localities mentioned by Hall, the 

 fossils answering to his description, and they are identical 

 with Ra?raer's forms." 



I was certainly in ignorance of this " bar," and I now know 

 that it is a frivolous impediment. In fact, if I had suggested 

 this weak piece of reasoning, Dr. Hinde would have been 

 justified in considering that I had not been paying compli- 

 ments to his intelligence as a zoologist. Hindia sphoevoi- 

 dalis, mihi, is the correct name of the fossil. 



The concluding part of Dr. Hinde's next paragraph places 

 me in a difficulty. He considers that I have made errors of 

 observation, " which, to spare Prof. Duncan, it would be prefer- 

 able to pass over in silence." If that remark is sincere, and 

 really means what it states and infers nothing else, I can only 

 say that, whilst I am obliged to Dr. Hinde for his good will, 

 I decline to let him or anybody else sacrifice the cause of truth 

 to save my feelings. I have never permitted and shall never 

 allow personal considerations to stand in the way of the truth. 

 I venture to state that I have never hesitated to admit an error 

 when I was satisfied that it was one, and to make all the 

 compensation possible. But if there is any other and unchari- 

 table meaning to be applied to Dr. Hinde's words, I must say 

 that they were written in the worst possible taste. 



The subjects at issue are the mineral condition of the fossil 

 and the nature of Paheachlya. I stated, and it is undeniable, 

 that the spicules are calcareous, and that they are penetrated 

 by an organism which did not, judging from the modern 

 example, live in silica. I hold to that opinion as true, and 

 the slightest examination of the papers I have written on 

 PalceacJilya and its modern representative, and their com- 

 parison with the paper on the nature of the alga which enters 

 and destroys the siliceous spicules of the present day, will 

 suffice to show that there is no contradiction on my part. 

 The silica-perforating organism in no way resembles Palce- 

 achlya, and there are no proofs of its presence in Hindia 

 sphmroidalis. 



It appears that the Palceaclilya passed in and out of the 

 sponge-spicules and is now seen in the infilling mineral, which 

 1 venture to maintain was calcareous originally, and doubtless 

 full of organic matter when it was first introduced. This 

 belief is quite unaffected by the possible grave error of inter- 

 pretation — not of observation — of which Dr. Hinde accuses 

 me at second-hand, following Dr. RaufF. When I read Dr. 

 Rauff's exceedingly considerate and truly scientific paper I 

 was greatly exercised in my mind about the tremendous mis- 

 take I had made in taking silica to be calcite and an'agonite. 



