CEISIXA . 
163 
Eeptotubigera calypso, Bucaille, 1890. Bry. Cret. Seine-Inf. : Bull. Soc. Sci. 
nat. Ronen, vol. xxv. p, 507. 
Crisina normaniana, d’Orbigny, 1850. Prod. Pal. vol. ii. p. 265. 
,, ,, d’Orbigny, 1851. Bry. Cret. pi. 612, figs. 1-5. 
,, ,, d’Urbigny, 1851. Ibid. p. 914. 
,, ,, Pergens, 1890. Revision, p. 347. 
Idmonea ,, Bucaille, 1890. Op. cit. p. 510. 
Crisisina triangularis, d’Orbigny, 1851. Bry. Cret. pi. 612, figs. 11-15. 
Crisina 
Idmonea 
,, dor sat a, 
Crisina ligeriensis, 
> > 5 ) 
Idmonea prima, 
d'Orbignv, 1853-4. Ibid. p. 915, pi. 769, figs. 11-14. 
Pergens, 1890. Revision, p. 348. 
Pergens, 1893. Bry. St. Pat. : Bull. Soc. beige Geol. 
vol. vi. p. 204. 
Pergens, 1895. Bry. Arcbe de Leves : Bull. Soc. beige 
Geol. vol. viii. p. 134. 
Pergens, 1895. Bry. Cachemb. : Bull. Soc. beige Geol. 
vol. viii. p. 182. 
Vine, 1889. Polyz. Greensd. : Proc. Yorks. Geol. Soc. 
vol. xi. p. 260. 
d’Orbigny, 1850. Prod. Pal. vol. ii. p. 265. 
d’Orbigny, 1851. Bry. Cret. pi. 614, figs. 11-15. 
Pocta, 1892. Mech. Koryc. Ilory: Cesk. Akad. Cis. Fr. Jos. 
sect. ii. p. 18, pi. ii. figs. 7-11. 
Diagnosis. 
Zoarium of dichotomous branches, forming a small tuft. The 
reverse surface is rounded and convex ; the obverse face is 
a blunt ridge : hence in transverse section the branches appear 
suhtiiangular, with a rounded base. The reverse surface is 
slightly linearly furrowed. 
Apertures in cuiwed, vertical rows of from two to five, hut 
generally four ; the rows of peristomes form well-raised crests, 
and the rows are well spaced. 
Gonoecium lateral ; subspherical ; thrice the diameter of the 
zooecia. 
Dimensions. 
Type form Var. triangularis Var. normaniana B.M. 
Pergens). Pergens). Pergens) . D. 973. 
Diameter of branches -5 mm. ... '5 mm. ... *5 mm. ... 1 mm, 
Diameter of zooecia •1--12 ,, ... *15 ,, ... *16 ,, ... -2 ,, 
Diameter of apertures -05 ,, ... '05 ,, ... *08 ,, ... 'l-GS ,, 
Distance of peristomial 
series ... ‘3-'42 ,, ... *03 ^,, ... •35-’5,, ... *7 ,, 
^ Probably a misprint for -3. 
