310 
IfODELEA. 
3. Nodelea durobrivensis,^ nov. 
Diagnosis. 
Zoarium of tMii branches. 
Zooecia varying in external shape from sub-hexagonal to kite- 
shaped, being rounded and arched above, and tapering to 
a sharp point below. The interzooecial margins are more or 
less distinct. 
Apertures subcircular or subtrigonal ; large. The peristomes 
are raised well above the general surface. They occur quin- 
cuncially, in spirals ; but locally they are irregular. 
Closed cells numerous ; the cap is complete or pierced by a pore ; 
and a pore pierces the front wall of some zooecia. 
Gonocysts projecting, piriform, and large. 
Dimensions. 
B.M., D.4U2. B.M.,D.2699. B.M., D. 2718. 
Diameter of branch ... 1’8 mm. ... l‘o mm. ... \'b mm. 
Diameter of zooecia ... *3 ,, ... -5 ,, ... -30 ,, 
Diameter of aperture ... *2 ,, ... *2 ,, ... •16-*20 ,, 
Disteibijxion. 
British : 
Upper Chalk : Bromley ; Gravesend ; Clarendon, 'Wilts, in zone of 
BclcmniteUa mucronata. 
Middle Chalk : Chatham. 
Chalk: Dover. 
Figures. 
PI. XI Y. Fig. 4. Part of a zoanum in which most of the 
zooecia are closed, sometimes with a conical, perforated cap ; one 
zooecium has two pores in the wall below the -peristome ; 
a broken gonocyst also occurs : X 1 5 dia. Middle Chalk : 
Chatham. Vine Coll. D. 2718. 
PL XI Y. Fig. 5. Part of a branch in which the front walls of 
the zooecia are tumid ; many of the zooecia are closed : X 8 dia. 
Middle Chalk : Chatham. Gamble Coll. D. 4112. 
PI. XIY. Fig. 6. Part of a zoarium with more widely spaced 
zooecia, some of which are closed and some have a sub-peristomal 
pore; X 10 dia. Middle Chalk : Chatham. Vine Coll. D. 2699. 
From Durobrivis, the Koman station near Chatham. 
