W, D. Lang—Cretaceous Polyzoa of the Family. Idmoniide. 127 
B. Branches of zoarium, if anastomosing, form only a loose network, the meshes of 
which are flame-shaped. 
‘I. Zoarium very compressed in a plane at right angles to that of the obverse and 
reverse faces, being about tive or six times as high as wide. 
a. Apertures about seven in a series. 
Reticulipora papyracea, V@Orbigny: 1851, Bry. Crét., pl. 611, 
figs. 1-5; 1853, Bry. Crét., pl. 768, figs. 3-10. 
Reticulipora complanata, Marsson, 1887, Bry. Riig.: Pal. Abh., 
vol. iv, pl. iii, fig. 10. 
Reticrisina papyracea, Gregory, 1899: B.M. Cat. Cret. Bry., 
vol. i, pl. ix, figs. 1-3. . 
b. Apertures twelve to twenty in a series. 
Reticulipora obliqua, d@Orbigny: 1851, Bry. Crét., pl. 610, 
figs. 1-5 ; 1853, Bry. Crét., pl. 768, figs. 1, 2. 
Reticrisina obliqua, Gregory, 1899: B.M. Cat. Cret. Bry., vol. i, 
p. 177, fig. 13; pl. viii, figs. 8, 9. 
II. Zoarium compressed in a plane at right angles to that of the obverse and 
reverse faces, but only three or four times as high as wide. Apertures 
about nine in a series. 
Cricopora gradata, Leymerie, 1851, Type. Pyren. par. a Craie : 
Mém. Soc. géol. France, ser. 11, vol. iv, pl. ix, fig. 7 
III. Zoarium only slightly, if at all, compressed in a plane at right angles to that 
of the obverse and reverse faces. 
Retepora disticha, purs, Goldtuss, 1827: Petref. ne vol. i, 
pl. ix, figs. 15e, d 
Idmonea disticha, yon Hagenow, 1851: Bry. Maastr. kr., pl. ii, 
fig. 8. 
Idmonea maculata, pars, yon Hagenow, 1851: Bry. Maastr. kr., 
pl. ui, figs. 3e-g. 
Tubigera distiqua, Postion: 1853: Bry. Crét., pl. 746, figs. 2-6. 
Ceriopora subcompressa, von Hagenow, 1845: in Geinitz, Grundr. 
Verst., pl. xxiiid, fig. 15. 
Idmonea subcompressa, Marsson, 1887, Bry. Riig.: Pal. Abh., 
vol. iv, pl. ii, fig. 7. 
Stichopora regularis, d’Orbigny, 1851: Bry. Crét., pl. 613, 
figs. 11-15. 
Tubigera antiqua, @’Orbigny, 1853: Bry. Crét., pl. 746, fig. 1. 
Tubigera distans, d’ Orbigny, 1853: Bry. Crét. , pl. 746, fies, 7-11. 
Reticrisina disticha, Gregory, 1899: B.M. Cat. Cret. Bry., 
vol. i, p. 184, fig. 14. 
TERVIA. 
A.- Zocecia one or tio in a Jateral series. 
1. Distance between the series of apertures two to three times the diameter 
of an aperture; zoarium cylindrical; zocecia immersed; distance 
between apertures of the same series one diameter of an aperture. 
Crisina subyracilis, d’Orbigny, 1851: Bry. Crét., pl. 614, 
figs. 6-10. 
Idmonea subgracilis, Pergens, 1890: Revision, pl. xii, fig. 2 
2. Distance between the series of aper fures four times the diameter of an 
aperture ; zoarium flattened in the plane of the obverse and reverse 
faces ; zocecia immersed ; distance between apertures of the same 
series one diameter of an aperture. 
Filisparsa pulchella, Marsson, 1887, Bry. Riig.: Pal. Abh., 
vol. iv, pl. iu, fig. 7. 
3. Distance between the series of apertures four to seyen times the diameter 
of an aperture. 
a. Apertures one only in a series; zoarium flattened in the plane of the 
obverse and reverse faces ; zocecia immersed or boundaries slightly 
shown. 
T. subgracilis. 
