152 
IDMOXEA. 
D. 3026. 
D. 3139. 
D. 4504. 
D. 4505. 
D. 3140. 
D. 3141. 
A zoarium on a chert pebble. Lower Greensand. Farringdon. 
Old Coll. 
A large zoarium encrusting a cast of a lamellibranch. Lower 
Greensand. Farringdon. Old Coll. 
A large zoarium, with Prohoscina crassa (Rom.), var. divaricata 
(Orb.). Lower Greensand. Farringdon. Cunuington Coll. 
A zoarium with a base of an Entalophoroid encrusting a chert 
pebble. Lower Greensand. Farringdon. Cunuington Coll. 
Two zoaria, with Prohoscina, sp. Lower Greensand. Farringdon. 
Charles worth Coll. Purchased 1871. 
Two zoaria, wuth Prohoscina, sp. Lower Greensand. Farringdon. 
Charlesworth Coll. Purchased 1871. 
2. Idmonea alipes,^ nov. 
Diagnosis. 
Zoarium of a long median ridge, bounded by a broad wing- like 
selvage. The ridge in transvei'se section is triangular. The 
selvage is usually marked by divergent, cuiwed ribs ; but 
it may be smooth. The zoarium is unbiunched, but two 
zoaria often diverge fi'om the same point. 
Apeiimres uniserial at the proximal end, but at the distal end 
they may be triserial, or even quadriserial or quinqueserial. 
The transverse series are near together, 
raised. 
Peristomes slightly 
Dimensions. 
D. 3843. 
Length of zoarium 
9 mm. 
"Width of zoarium 
4 
Width of ridge 
•4-1-3 „ 
Diameter of zooecia ... 
•12--20 „ 
Diameter of apertures 
•08-1-4 ,, 
Distance of peristomial series ... 
•4--5 ,, 
Disteibution. 
Middle Chalk : Chatham. 
Figtjees. 
PL YIII. Pig. 2. A zoarium in which the zooecia appear some- 
what irregularly arranged when seen from above, but which on 
1 I.e. ‘wing-footed.’ 
