THOLOPOEA. 
273 
identification of the Crag fossil seems correct, so that the species 
is quite distinct from the Cenomanian Tholopora. 
LIST OT SPECIMENS. 
D. 3628. A stout zoariura, 6 mm. long and 5 mm. diameter. Cenomanian — 
Essener Griinsand. Essen. Old Coll. 
D. 3620, A specimen 14 mm. long by 5 mm. in diameter, and with strongly 
annulated stem. The rows of apertures are short, containing only 
from six to seven. Cenomanian — Essener Griinsand. Essen. 
Old Coll. 
D. 3684. A small zoarium, 4 mm. in diameter and 3|mm. high, with from 
twelve to fourteen apertures in the longest vertical series. A small 
central axial group of equal zooecia. Cenomanian. Le Mans. 
Tesson Coll. 
D. 3686. Seven zoaria and fragments (in tube). One has a spherical top with 
a fragment of the peduncle ; it is 4 mm. in diameter and 3 mm. 
high, and has seventeen apertures in the vertical series. The 
largest specimen is 5-5 mm. high, 3 mm. in diameter; it has 
a young zoarium attached to it, I5 mm. in diameter, with distinct 
radial arrangement of apertures. Cenomanian. Le Mans. Tesson 
Coll. 
2. Tholopora nmletiana (d’Orbiguy), 1850. 
Synonymy. 
Ceriopora mtiletiana, d’Orbigny, 1850. Prod. Pal. vol. ii. p. 121. 
Bomopora ,, d’Orbigny, 1854. Bry. Cret. p. 988, pi. 781, figs. 1-4. 
,, ,, pars, Osswald, 1890. Bry. Meckl. Kr. : Arch. Ver. 
Mecklenb. vol. xliii. p. 105. 
Diagnosis. 
Zoarium consists of a large knob-shaped cluster of zooecial 
groups, on a short, cylindrical, constricted stem. Centres 
of sub-colonies consist of depressed area occupied by apertures 
all equal in size. About six to eight apertures in each 
radial row. Mesopores large. 
Disteibution. 
Aptian : Les Croutes, Aube ; Gurgy, Yonne ; Vassy, Haute-Marne. 
Hauterivian : Cressier, near Neuchatel. 
Affinities. 
This species is allied to R. hosquetiana (Hag.) by its zoarialform, 
but differs in the smaller number of apertures in the radial rows 
and in the marked constrictions on the stem. The species has 
some resemblance to Radiopora, owiug to the massive expansion 
T 
