Mr. II. J. Carter on the Poljtremata. 201 



between Polytrema and Car'penteria^'^ but that this arose from 

 Carpenter's spechnens of Po^y^rema, according to Max Schultze, 

 having contained " no spicules in their interior." How this 

 could be I know not, seeing that the specimens of Polytrema 

 which Dr. Carpenter gave me did, as I have stated, contain 

 spicules in their interior ('Annals,' 1870, vol. v. p. 391). 



Lastly, Dr. Carpenter observes (for he is the only authority 

 on this subject), "it is not a little curious that there should 

 be a strong external resemblance between Polytrema and some 

 of the less regular forms of Carpenteria — a resemblance which 

 is increased by the presence of free openings at the extremities 

 of the branches in the former, and by the precise conformity 

 which its areolation often presents to that of Carpenteria, The 

 relation, however, is one of mere isomorphism, as we have 

 seen the internal structure of the two organisms to be essentially 

 different " {op. cit. p. 237). To me the " internal structure" 

 is, mutatis mutandis^ " essentially " the same. 



Possessing a view so totally different from that of Dr. Car- 

 penter with respect to Polytrema and Carpenteria, and so 

 opposed to the suggested hybrid nature of the latter, to which 

 the former must be now added as equally containing sponge- 

 spicules in its internal cavities, and therefore equally presenting 

 a form half foraminiferous and half spongeous, it may not be 

 considered useless to endeavour to get rid of this mythical im- 

 pression altogether by substituting liisso's generic name of 

 ^^ Polytrema^'' for Gray's ^^ Carpenteria,^^ and qualifying it by 

 the significant designation of halaniforme, in accordance 

 with Dr. Carpenter's well suggested resemblance of the 

 latter to Palanu$, with which no doubt it has often been 

 confounded. 



When writing on the species of Foraminifera which I termed 

 ConuUtes Cookij Dr. Carpenter states, "The fossil described 

 by Mr. Carter under the new generic name of ConuUtes does 

 not appear to me to differ so essentially from the preceding in 

 general plan of structure as to require being generically sepa- 

 rated from it;" and thus my ConuUtes was changed to ^'Patel- 

 lina Coohi'''' {op. cit. p. 233). I might say the same with 

 reference to Carpenteria.^ had I not stronger grounds to go upon 

 than Dr. Carpenter seems to me to have had in changing my 

 name of ConuUtes to PatelUna. 



Again, when I discovered that the organism which Dr. 

 Bowerbank had placed, and still continues to place, among the 

 British sponges under the name of '"'' Halyphysema Tumano- 

 xoiczii'' (Mon. Brit. Spong. vol. ii. 1864, and vol. iii. 1873, 

 pi. xiii.) was not a sponge but a foraminiferous animal, and 

 published an illustrated description of it ('Annals,' 1870, vol. v. 

 Ann. & Mag. N. Hist. Ser. 4. Vol. xyh. 14 



