CELLULAMNE AND OTHEE POLYZOA. 307 
Dkhjmozoum, nom. nov. — See Didymia. 
Limetopia, Busk, 1852', p. 384. — Genosyutypes, D. spieata and D. cornuta, Busk, 
n. spp. See also Busk, 1852\ p. 35. In 1909 Prof. A. Billard submitted to 
me a specimen of Dynamena harhata, Lamx. (1816, p. 178), from Lamouroux' 
type -collection at Caen; and I convinced myself that D. spieata, Busk, was a 
synonym of this species (see Billard, C.B. Acad. Sci. Paris, 1909, cxlviii. 
p. 1064). In the apparent absence of an earlier selection I propose Bime- 
topia cornuta as the genotype. It appears to me preferable to select a species 
of which good figures were published by Busk, rather than to choose B. harhaia, 
the identification of which with B. spieata rests merely on my own authority. 
/Dimorpliozoum, Levinsen, 1909, pp. 96, 107. — Genotype (the only species), 
Bimorphozoum nohile {Flustra nohilis, Hincks, 1891, A. M. N. H. (6) vii. 
p. 288), 
Biplodidymia, Eeuss, 1869, Sitzb. Akad. Wiss. math.-nat. 01. lix. i. Abth. p. 468. — 
Genotype (the only species), Diplodidymia complicata, Reuss, n. sp. Synonym 
of Forieellaria , D"Orbigny, 1852. 
Bittosaria, Busk, 1866, Geol. Mag. iii. p. 301. — Genotype (the only species), 
Bittosaria loetherellii. Busk, n. sp., a fossil, from the London Clay, perhaps 
allied to Sertularia loricata, L., the genotype of Eucratea (q. v.). 
Emma, Gray, 1843, p. 293. — Genotype (the only species), Emma crystallina, Gray, 
n. sp. Gray gave no generic diagnosis, but this was done by Busk, 1852 ', 
p. 372, and 1852 =, p. 27. 
JSpistomia, Fleming, 1828, p. 541.— Genotype, selected by the author, Epistomia 
hursaria {Sertularia hursaria, L., 1758, p. 814). See Gregory, 1893, Trans. 
Zool. Soc. xiii. p. 227. See also Notamia. 
JErina, Cami, 1908, Ann. Mus. Nac. Buenos Aires (3) x. p. 273. — Genotype, selected 
by the author; Erhm patagoniea, Canu, n. sp., placed in Meliceritidse. Pre- 
occupied by Erina, Swainson, 1833, Zool. lUustr. (2) iii. pi. 134 (Lepidoptera).' 
■Eucratea, Lamouroux, 1812, p. 183. ^Genosyutypes, Oellaria cornuta {Sertularia 
cornuta, L., 1758, p. 810) and 0. loricata {Sertidaria loricata, L., 1758, p. 815). 
In the same Memoir Lamouroux introduced the genus Orisia {q. v.). Each of 
these genera included one species, S. cornuta and S. eburnea respectively, 
belonging to Crista as universally understood at the present time. It is 
unfortunate that Schweigger (1819, Tab. 8; 1820, p. 429) indicated 
S. cornuta as the genotype of Eucratea, and S. ciliata as the genotype of 
Orisia ; both of Lamouroux' genera being regarded by him as subgenera of 
Gellularia. By adopting these selections Bicellaria, auctt., would become a 
synonym of Orisia, and Orisia, auctt., of Eucratea. These alterations would 
be so inconvenient and confusing that I feel justified in suggesting that 
Schweigger's selections should be ignored. If Orisia is to be maintained, its 
genotype must be Orisia eburnea (Linn.), and S. cornuta will fall within the 
same genus ; Eucratea loricata (Linn.) thus remaining as the genotype of 
Eucratea. S. ehelata, L. (1758, p. 816), which has usually been regarded as 
the genotype of Eucratea, has no claim to this position, as it was not included 
"in Eucratea by Lamouroux until 1816 (p. 149). 
