SPIEOPOEA. 
263 
Di:m:ensioxs. 
Per< 2 rens, 
p. 359. 
Diameter of branch ... — 
Diameter of zocecia ... •18-*20mm. 
Diameter of aperture .. . -06 ,, 
Distance of rows of 
apertures — 
Pergens, 
B. 4449. 
p. 365. 
D. 946. 
Type oi jessoni, 
— 
1 mm. 
’7 mm. 
S--36 mm. 
•2--25 „ 
•15-17 „ 
•11 n 
•12--15 ,, 
•12 „ 
— 
•.'5-7 „ 
•1 „ 
Disteibutiox. 
Exgland : 
Upper Chalk : Salisbury ; Bromley. 
Middle Chalk : Chatham. 
Chalk : Charing, Kent. 
Upper Greensand : Cambridge jessoni). 
Foreign ; 
Senonian — Maastrichtian : Meudon ; Fecamp, Seine -Inferieure ; Eoynn. 
Campanian : Riigeu. 
Santonian : Saintes, Charente-Inferieure ; L’ Arche de 
Leves and Cachembach. 
Coniacian : Yendome, Lisle, Lavardiu, etc., Loir-et-Cher ; 
Jone, Tours, Sainte-Paterne, La Bibochere, etc., Indre- 
et-Loire. 
Turonian : Angouleme and ;^[erpins, Charente ; Martigues, Bouches- 
du-Bhone ; Yillardin, Loir-et-Cher. 
Cenomanian : Le Maos, Sarthe ; Havre, Seine-Inferieure ; Essen. 
Figtjees. 
PI. XI. Pig. 6. Two parts of the same zoarium, showing 
verticillate and spiral arrangements of apertures ; X 10 dia. 
Upper Chalk : Salisbury. Yine Coll. D. 946. 
PI. XI. Pig. 7. A fragment of the micropora variety, showing 
passage from verticillate to pinnate arrangement of apertures ; 
X 7 dia. Middle Chalk : Chatham. Yine Coll. D. 662. 
PI. XI. Pig. 8. A hollow zoarium of the Semilaterotuhigera 
variety. Pig. from the side ; Pig. 85, from the end : X 7 dia. 
Middle Chalk : Chatham. Gamble Coll. D. 470. 
PI. XI. Pig. 9. A specimen of the var. jessoni, X 10 dia. 
Upper Greensand ; Cambridge. Yine Coll. B. 4449. 
PL XI. Pig. 10. Part of base of stem of jessoni^ X 10 dia. 
Upper Greensand : Cambridge. Yine Coll, B. 4447. 
