MEUCERITITES. 
343 
12. Meliceritites semiluna, d’Orbigny, 1853. 
Synonyity. 
Meliceritites semiluna, d’Orbigny, 1853. Bry. Cret. p. 623, pi. 736, figs. 20, 21. 
„ semiclausa, pars, Pergens, 1890. Revision, p. 394. 
,, „ Gann, 1897. Bry. St. Cal.: Bull. Soc. geol. Fr. ser. 3, 
vol. XXV. p. 751. 
Diagnosis. 
Zoarium of thick, dichotomous branches. 
Apertures very large, round above, with a straight lower margin. 
Front wall a narrow triangular area, much smaller than the 
aperture. 
Avicularia twice as long as the zooecia. 
Disteibution-. 
British : 
Middle Chalk : Chatham. 
Foreign : 
Senonian — Coniacian : Tours and done, Indre-et- Loire ; Bougniaux 
and Peguillac, Charente-Inferieure. 
Turonian : Yillardin, Loir-et-Cher. 
Figtjee. 
!N’o. 40. Part of a branch with avicularium, X 20 dia. Middle 
Chalk : Chatham. Gamble Coll. D. 358. 
Fig. 40. — Meliceritites semiluna, Orb. 
Affinities. 
This species is the Senonian representative of M. vendinnensis. 
It is characterized by its large aperture and small trigonal front 
wall. The species differs from M. vendinnensis by its long spatulate 
avicularium. 
