Miscellaneous, 85 



the genus Grantla, to which the specimen of calcareous sponge which 

 is the type of Alcyoncellum gelatinosurn of the 'Manuel d' Actinologie ' 

 decidedly belongs ; and unless it be determined that genera founded 

 on manifest errors are, rightly or wrongly, to maintain their places 

 in science, the calcareous type of the genus in question must give 

 place to the siliceous one of Quoy and Gaimard. 



The same course of argument applies to the genus Euplectella, 

 also founded in error, as any one who will refer to the original paper 

 descriptive of the type specimen, in the ' Transactions of the Zoo- 

 logical Society,' vol. iii. p. 203, will plainly see. 



It would lead to inextricable confusion of dates if we were to 

 accept as the date of a work the year in which it was said to have 

 been commenced. The criterion of date is that on the titlepage ; 

 and this is the only one that we can accept as the date of a genus 

 first published in a volume — or, in the case of a paper, that on which 

 it was publicly read in an established Society. 



I take this opportunity of replying to some assertions made by 

 Dr. Gray, in his paper " Observations on Sponges and on their Ar- 

 rangement and Nomenclature," published in the 'Annals ' for March 

 1868. On page 167 he states, " It is to be observed that though I 

 have Dr. Bowerbank's own authority for regarding MacAndrewia 

 azorica as identical with Dactylocalyx Prattli," &c. I distinctly 

 deny having ever, in writing or orally, given Dr. Gray to understand 

 that I for a moment considered his MacAndrewia and my Dactylo- 

 calyx Praitii as being the same species ; and the remainder of the 

 paragraph, of which I have quoted the first portion, certainly does 

 not in any way prove Dr. Gray's very erroneous assertion. Again, 

 in page 168, Dr. Gray says, " I have Dr. Bowerbank's authority 

 for considering the latter [D. Prattii] a synonym of M. azorica, 

 he, when examining the specimens in the British Museum, having 

 brought to me, as a good example of his Dactylocalyx Prattii, the 

 specimen I described and figured, not recognizing it as the sponge 

 to which he had already given two other names (I believe the Indian 

 habitat is a mistake) ; so that this sponge has been referred to two 

 genera and regarded as three species by Dr. Bowerbank." The as- 

 sertions of Dr. Gray in the above quotation are just as unfounded 

 as the first one. Long before the interview alluded to by Dr. Gray, 

 I was too well acquainted with the structural characters of both his 

 MacAndrewia and my Dactylocalyx Prattii to allow me for one mo- 

 ment to consider them otherwise than as distinct species, having 

 carefully examined the structures of both specimens, and having the 

 results of my examinations mounted in Canada balsam, long before 

 the interview with Dr. Gray at the British Museum, the examina- 

 tion of the Doctor's MacAndrewia azorica having been effected inl860, 

 very shortly after the publication of the species in the 'Pro- 

 ceedings of the Zoological Society.' The only reference that was 

 made to the two specimens was, that I pointed out to Dr. Gray that 

 the specimen of his MacAndrewia azorica was in as perfect a state of 

 preservation as my Dactylocalyx Prattii ; but I never for one moment 



