68 BRITISH FOSSIL CORALS. 
only by characters of secondary value, which agree, however, very well with those of the 
other Corals belonging to the same generical division. Sep/a forming four complete cycla ; 
exsert, thick exteriorly, but thin inwardly, and presenting but few granulations on their 
lateral surfaces. Those of the second cyclum almost as large as the primary ones; the 
tertiary ones but little developed, although they correspond to large costa, and not as tall 
as those of the last cyclum, which are grouped very closely on each side of the primary and 
secondary ones. Height of the corallum, one inch two or three lines; great diameter of 
the calice, six or seven lines. 
The genus Bathycyathus contains two other species, which are both recent : B. Chilensis' 
and B. Indicus,’ which differ from B. Sowerbyi in having an additional cyclum of septa, 
the calice arched, and the costee more developed near the basis. We have seen but two 
specimens of this fossil; one, belonging to the collection of Mr. D. Sharpe, is catalogued 
as having been found in the Gault near Folkstone; the second, belonging to the museum 
of the Geological Society, is referred with doubt to the upper greensand of Kidge, in 
Wiltshire. 
Family ASTREID® (p. xxii). 
Tribe EUSMILIN A (p. xxi). 
1. Genus TROCHOSMILIA (p. XXIV). 
TrocHosmiLia sutcata. ‘Tab. XI, fig. 6, 6a, 64. 
Corallum simple, turbinate, straight, tall, much compressed, subpedicellate, and ap- 
pearing to be free. /Wa// presenting on each side two deep longitudinal furrows. Coste 
distinct from the basis, slightly prominent, closely set, and unequal, especially towards their 
upper end. Cadlice elliptical, sublobulated, and slightly arched ; its long and short axis in 
the proportion of 100:200. Fosswla very narrow, elongated, and not very deep. No 
columella. MSepta forming four cycla or more, rather unequal, closely set, thin, and slightly 
exsert. Déssepiments not numerous. Height of the corallum, nearly one inch; diameter 
of the calice, six or seven lines by three ; depth of the fossula, two lines and a half. 
We have seen but one specimen of this fossil, which, although somewhat weather-worn, 
appeared sufficiently distinct from all other species to authorise us in giving it a peculiar 
specific name. It differs from Zrochosmilia didyma’* by its calice beg straight, and not 
1 See our Monograph of Turbinolide, tab. ix, fig. 5. 
Loe. cit., tab. ix, fig. 4. 
5 Turbinolia didyma, Goldfuss, Petref. Germ., vol. i, tab. xv, fig. 11. 
