204 DR. a. J. HIXDE ON SEPTASTE^A, d'oRBIGNT (1849), 



possess either columella or pali. De Promentel, in the ' Paleontologie 

 Francaise'*, again repeats the diagnosis of the genns, with the 

 addition that the lamina, which sometimes occurs in the centre of 

 corallites about to divide, is only the extension of a long septum. 

 The two species from the Cretaceous rocks of France which he 

 introduces into the genus do not, however, any more than the 

 Liassic species, properly belong thereto. 



In the " Revision of the Families and Genera of the Madre- 

 poraria"t, Prof. P. M. Duncan gives a definition of Septastrcea, 

 similar in the main to that of Edwards and Haime ; but the colu- 

 mella is stated to be rudimentary or absent, and there is " fissiparity 

 of calices ":p. The genus is included with three others in the 

 " Alliance Goniastrseoida," which consists of massive fissiparous 

 Astraeidse, having, with other features, dentated septa. It will be 

 noted that this author, in opposition to Edwards and Haime, asserts 

 that there may be a rudimentary columella in the genus, and further 

 that the mode of growth is by fissiparity of the calices, whereas 

 the French authors are doubtful on this latter point, and state 

 that the growth may possibly be submarginal, i. e. by budding. 



In the paper in the Quarterly Journal of Feb. 1887, p. 25, 

 treating of the new genus Glypliastrcea^ the same author again 

 reverts to Septastrcea^ and requotes the definition given of it by 

 Edwards and Haime. He further states that the Mesozoic species 

 introduced into the genus by himself and de Fromentel do not agree 

 with the Tertiary species originally placed in the genus by d'Orbigny 

 and Edwards and Haime, and he therefore takes the original species 

 of the genus for the type of a proposed new genus Glyphastrcea^ 

 and leaves in Septastrcea those Liassic forms which, according to 

 his own confession, do not belong to the genus as originally con- 

 stituted. 



But in those cases in which species have been erroneously included 

 in a genus, the established and common-sense rule is to regard the 

 species which the author of the genus originally included in it as 

 its type, and if other species are subsequently introduced into the 

 genus either by the same author or by other writers which do not 

 agree generically wdth the type form, these subsequent species 

 should be removed from it and placed elsewhere. But Prof. 

 Duncan has actually reversed this order ; for instead of removing 

 from Septastrcea the Jurassic species, which, by himself and Fro- 

 mentel, have been erroneously placed in it, many years after it had 

 been established, and which, as acknowledged by himself, are not 

 congeneric with the original Tertiary forms, he severs from the 



* Tome viii. livr. 28, Juin 1879. 



t Linnean Society's Journal, Zoologj', vol. xviii. (1884), p. 103. 



\ 'Prof. Duncan states, in his paper on GlyphastrcBa (Q. J. G. S. vol. xliii. p. 25), 

 " the only important modification I made in revising the genus \i. e. Sep- 

 tastrcsa] -^vas to introduce the necessary statement that increase took place 

 by gemmation as well as by fissiparous division of the corallites," and he refers to 

 p. 108 of the " Eevision" in the Linn. Soc. Journal. On turning to the reference 

 given, however, I do not find any mention whatever of the statement about 

 gemmation therein. 



