DIASTOPOEIT)^, IDMONIIDJE. 
295 
Chak. — Zoarium with radial dichotomous ridges, the upper surface of Avhich 
is rounded. Rows of apertures usually opposite, about three in a row on each 
slope. Fifteen rows of apertures in 3 mm. Apertures ’08 mm. in diameter. 
O O 
Distrib. — Senonian — Campanian— Ahussandsten : Ahus, Sweden. 
Aff. — This species is a near ally of I. triangularis (Hennig), from which it 
differs by its rounded and dichotomous ridges. In the former respect it agrees 
with I. hagenowi (Sharpe). This species was referred by Hennig to Semiclausa, 
but he describes the zoarium of that genus as the same as in Reptoclaiisa ; 
but the only difference between those genera is zoarial ; hence Hennig’s 
Semiclausa and his Reptoclaiisa are the same. 
6. triangularis (Hennig), 1894. 
Syn. Reptoclaiisa triangularis, Hennig, 1894. Bry. Sver. Krit. ii., Cycl. : 
Lunds Univ. Arsskrift, vol. xxx., Acta 
Physiogr. Ho. viii. p. 8, pi. i. fig. 1. 
non Idmonea ,, Pergens, 1890. Rev. p. 348 (and other memoirs, 
for which see Cat. Vol. I. p. 163). 
Char. — Zoarium with short triangular ridges, many of which are short and 
detached. Apertures in roAvs of from two to four on each slope of the ridge. 
Rows alternate ; about twelve rows in each length of 3 mm. Apertures 
•08 mm. m diameter. 
Distrib. — Senonian— Campanian : Zone of Belemnitella mucronata, Kopinge ; 
beds with Actinocamax mamillatus, Gropemollan and 0. Karup, Sweden. 
Aff. — The nearest ally of this species is I. hagenowi (Sharpe), from the 
Farnngdon Sponge Gravels ; from that species it differs by its triangular 
carinate ridges and the smaller diameter of its apertures. 
RETECRISINA, Gregory, 1899. 
To Unrepresented Species on p. 186 add; 
2. meudonensis (d’Orbigny), 1851. 
Syn. Bidiastopora meudonensis, d’Orbigny, 1851. Bry. Cret. pi. 627, 
figs. 22-5. 
Fasciporina ,, d’Orhigny, 1853. Ibid. p. 694. 
Fascipara ,, Pergens, 1890. Rev. p. 377. 
,, ,, Canu, 1900. Geol. Romorantin : Bull. Soc. 
geol. France, ser. 3, vol. xxviii. p. 103. 
Char. — Zoarium of flat, laterally compressed branches, with crowded apertures 
on the front edge, and the apertures on the sides in curved linear series, in 
which the apertures are distant on the hinder part and become crowded near 
the front edge. 
Distrib. — Senonian — Maastrichtian : Meudon, near Paris. 
Santonian: Romorantin, Loir-et-Cher. 
