Measurements, in n. : — 



Length of the entire colony, fig. 9, measured in a straight line, 9,000 ; 

 Greatest diameter of right lobe, 1,330; 

 Width of the longer zooecial series, 360; 

 Longest diameter of orifices, about 100; 

 Width of ooeciopore, 110. 



Tubulipora Lamarck. 



Tubulipora Lamarck, 1816, "Hist. An. sans Vert", Ed. 1, II, p. 161. 

 Tubulipora Lamouroux, 1821, "Exp. Méthod.", p. 1. 



Tubulipora Harmer, 1S98, "Dev. Tubulipora", Quart. J. Mier. Sci., XLI, p. 90. 

 Idmonea Lamouroux, 1821, "Exp. Méthod.", p. 80. 



I have stated my conviction, on a former occasion 1 ) that Idmonea, as commonly understood, 

 is inseparable from Tubulipora. The first species given by Lamarck is T. transversa 2 ), which 

 from his synonymy appears to be identical with the species described by most authors as 

 Idmonea serpens, but which appeared to me to be more properly designated T. liliacea Pall. 

 This species is usually adnate, although showing some tendency to become erect. In this latter 

 form it has so marked a similarity to species like Idmonea atlantica auctt., that it is hardly 

 possible to separate it generically from that species, and therefore from a number of other erect 

 species which writers on recent Polyzoa are agreed in referring to Idmonea. It passes, on the 

 other hand, through species like T. phalangea and T. flabellaris to the flabellate, adnate species 

 which are usually regarded as constituting the genus Tubulipora. T. phalangea shows the 

 serial arrangement of zooecia in as pronounced a form as in any species of Idmonea, while 

 T. flabellaris may have a considerable proportion of its peristomes isolated, although others 

 may be arranged serially. T. aperta Harm. was characterised as a species in which the peristomes 

 are all isolated or in which the tendency to assume a serial disposition is only slightly marked. 

 There seems thus to be a continuous succession, among recent species, from the erect "Idmonea" 

 type, with strongly marked alternating series of zooecia, to the adnate, flabellate, " Tubulipora" 

 type, in some species of which the serial arrangement is wanting. 



While most writers on recent Polyzoa have distinguished Idmonea from Tubulipora by 

 its erect habit, a different view is taken by some Palaeontologists. Gregory 3 ) considers that 

 I triquetra, the only species included by Lamouroux in Idmonea, and therefore indubitably 

 the genotype, differs generically from "the erect forms attributed to Idmonea'. He accordingly 

 defines Idmonea as consisting entirely of adnate forms, and uses Crisina D'Orbigny for the 

 erect forms which by most authors are placed in Idmonea. For the flabellate, adnate species 

 referred by most authorities to Tubulipora, Gregory employs Phalangclla Gray '). I regret that 

 I cannot follow him in this usage, on the ground that the only two species included by Gray 



1) Harmer, S. F., 1898 (see ref. on p. 124), p. 88. 



2) This is the only species mentioned by Lamouroux (1821, p. 1); and, as pointed out by Gregory (1S99, "Cat. foss. Bry. 

 Brit. Mus.", "Cret. Bry.", I, p. 157), it thus became the genotype of Tubulipora. 



3) Gregory, J. W., 1899, t. cit., p. 150. 



4) Okay. J. E., 1S4S. "List Brit. An. Brit. Mus.", I, pp. 139, 149. 



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