BRITISH PAL^OGBNE BETOZOA. 259 



English Eocenes. Among the species which M. Jullien [No. 2, p. 501, pi. xvii. figs. 72, 

 73] has referred to his genus Tervia it most resembles Tervia soUdula. 



Species 4. Idmonea coronopus, Defrance, 1821. 



Syn. Idmonea corompus, Defrance, 1821, Diet. Sci. Nat. t. xsii. p. .565 (non Atlas, pi. xlvi. fig. 2, as 

 stated by Bronn) ; Blainville, 18.30, ibid. t. Ix. p. 385 ; id. 1831, Man. d'Actinol. p. 420 ; 

 Milne-Edwards, 1836, in Lamarck, Anim. sans Vert. ed. 2, t. ii. pp. 281, 282 ; id. 1838, 

 M(im. Crisi('es, Ann. Sci. Nat. Zool. ser. 2, t. ix. pp. 215, 216, pi. xii. fig. 3 ; Michelin, 

 1844, Icon. Zooph. p. 172, pi. xlvi. fig. 16 ; Bronn, 1848, Index Palseont. Nomencl. p. 606 ; 

 Lonsdale, 1850, in Dixon, Geol. Sussex, pp. 153-155, pi. ix. fig. 24 ; Hagenow, 1851, Biyoz. 

 Maastr. Kreidebild. p. 25 ; Lonsdale, 1878, in Dixon, Geol. Sussex, ed. 2, pp. 204-206, 

 pi. ix. [10] fig. 24; Harris and Burrows, 1891, Eoc. and Oligoc. Paris Basin, p. 61. 



Retepora trigona, Morren, 1828, Desc. Corall. foss. Belgio, Ann. Gron. p. 37, pi. x. figs. 1-3 

 (identification _^'rfe Michelin) ; Galeotti, 1838, Mem. Gciogn. Brabant, p. 187, pi. iv. fig. 13 ■ 

 Nyst, 1844., Coq. et Potyp. foss. Terr. Tert. Belg., Mem. Cour. R. Ac. Belg. t. xvii. 

 pp. 619, 620. 



Chrysisina coronopus, Mourlon, 1881, Geol. Beigique, t. ii. p. 180. 



Horrmra flabellifurmis, Vine (non Blainv.), Proc. Yorks. Geol. & Polyt. Soc. vol. xi. p. 166, 

 pi. V. fig. 15 ; id. ibid. vol. xii. p. 53. 



Diagnosis. Zoarium small, erect, rising from an encrusting, expanded base. The 

 branches fork several times ; they are triangular in section and well rounded behind ; 

 they end bluntly. 



Zooecia in short transverse series, alternately arranged. The zocecia are single at the 

 base, but rapidly increase to rows of four ; this decreases to three above. The inner- 

 most zooecia are the longest. 



Peristome even, usually oblong with rounded angles ; younger and isolated zooecia 

 have oval or even circular apertures. 



Wall granular. 



Distribution. British: Bracklesham Beds, Bracklesham (Brit. Mus., Dixon and 

 Vine Collections). — Foreign: Calcaire grossier, Fames, Grignon, Chaumont, &c. ; 

 Laekenien ; Uccle (near Brussels), de Foret, d'Assche. 



Figures. PI. XXXII. figs. 6 «, 6 6. 



Affinities and Differences. As this species belongs to the typical group of Idmonea it 

 clearly differs from Idmonea {Tervia) seriatopora, Eeuss. As there is no median line 

 of zocecia it differs from Idmonea gieheli, Stol. From the third British Eocene species 

 it may readily be distinguished, as in that the zocecia are always in alternate pairs. 



Genus Hokneea, Lamouroux, 1821. 

 [Lamouroux, No. 2, p. 41.] 

 Diagnosis, Pergens, 1889, No. 3, p. 353. 



Type species. Eornera frondiauXata (Lamarck), 1816, No. r, pp. 182, 183. 

 VOL. XIII.— PART VI. No. 6.— June, 1893. 2 p 



