68 Dr. G. J. Ilinde o» the Genus Hindia. 



of the ' Annals/ has sewed to clear up many of the doubtful 

 points in the structure of this spono-e, which had remained 

 unexplained in the original description * by Prof. Duncan and 

 in my own subsequent short notice t of it. I have recently 

 again studied the characters of the fossil from new and better 

 prepared microscopic sections, and, thanks to the generosity of 

 Dr. RaufF, I have had the opportunity of examining the 

 specimens and sections on which his descriptions were based, 

 as well as the admirable drawings made from them for his 

 forthcoming monograph. Before, however, commenting on 

 Dr. Rauff's observations on the genus, 1 wish to reply to two 

 objections brought against me by Prof. Duncan, in the Sep- 

 tember number of the 'Annals,' respecting my notice of 

 Hindia in the ' Catalogue of Fossil Sponges in the British 

 Museum,' p. 57. 



The first point raised by Prof. Duncan is that I have re- 

 placed the name " sjjJio?roidaIis,^^ given by him to the typical 

 species in 1879, by the name '^/I'brosa,^^ applied by Ferd. 

 EcemerJ to the same species in 1860. Prof. Duncan rightly 

 states, " that a species in order to be established must be so 

 described that other forms than the type can be recognized ;" 

 and he further alleges "■ that there is not a single sentence in 

 the descri])tion [Rcemer's], meagre as it is, that would lead 

 any one to distinguish the form I described from New Bruns- 

 wick as belonging to it ;" and " Ferd. Roemer not having 

 properly and practically described the form he studied, and 

 having placed it among the corals, I [^'. e. Duncan] do not 

 consider his species of any value whatever." 



If these statements of Prof. Duncan represented the whole 

 truth of the matter he would be fully justified in placing the 

 name ^'Jibrosa " on one side, and insisting, as he does, that 

 " Hindia splueroidalis is quite correct." But after a careful 

 examination of fossils like those named Calavwpora fibrosa, 

 Rcem., of which there are several examples in the British 

 Museum, and comparing them with Rcemer's descriptions 

 and figures^ I can affirm " that they have been properly 

 and practically described, so that other forms than the type 

 can be recognized ;" and though they have been erroneously 

 referred to corals, yet the specific name is not thereby invali- 

 dated. 



The explanation of this apparent strong contradiction is as 

 follows : — It happens that the forms from Tennessee studied 

 by Roemer are in the condition of silicified casts, in which the 



* Ann. & Mag. Nat. Hist. 1870, ser. 5, vol. iv. p. 84. 

 ■ ■ - ■ ' '" •' -- -" • Mas.' p. r,7. 



Tennessee/ p. 20, pis. 2, 2«, 2i. 



,tvnu. tx iuag^. xmiu. xijsl. j.o/;', t 

 t ' Catalogue Fossil Sponges Brit. Mas.' p. h7. 

 \ ' Die silurisclie Fauna d. westl. 



