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99 
HILL: GEOLOGY OF JAMAICA. ave 
DESCRIPTION OF SPECIES. 
TROCHOSMILIA, EDWARDS AND HAIME. 
Trochosmilia hilli, sp. nov. 
plate XXXVI. Figs. 1-4. 
Form irregularly cyathiform, with a stout thick pedicel about one half the 
length of the corallum. Height of corallum about 22 mm. The calice oval, 
with a slightly sinuous outline. Sreater diameter 23.5 mm.; diameter at 
right angles to the greater, in the plane containing the vertical axis, 15.5 mm. 
The coste are very fine, alternating in size, with beaded margins, as shown in 
Figure 3, Plate X XXVI. The crowded, very fine, beaded coste appear to be 
splendid specific characters. Septa very numerous, thin and crowded. One 
hundred and ninety septa were counted in the type. The systems and cycles, 
probably due to the irregular transverse outline of the calice, are not distinctly 
differentiated, but there appear to be six complete cycles. The total number 
of septa for a calice with six cycles is 192. The septal margins are not dentate, 
but there are striations extending across them perpendicular to the flat planes 
of the septa. The ce lieular fossa is rather shallow, the calice being wide 
open, with a small depression in the centre. No columella; the edges of the 
principal septa meet in the axial space. 
Locality. Catadupa, Jamaica (collected by R Ti Ball). 
Type. Museum of Comparative Zoölogy. 
Remarks. This species bears considerable resemblance to the Trochosmilia 
acutimargo of Reuss, from the Eocene of Monte Grumi, near Castel Gomberto, 
and Monte Carlotta,! Northern Italy. I would call especial attention to the 
specimen figured in Vol. XXVII. of the Denkschriften of the Vienna Academy 
of Seiences.? 
I had the opportunity to study the original figured specimen of this form 
in the University of Vienna geological collections. The chief difference 
between the two species seems to consist in the difference in the character of 
the costeo. The costeo of acutimargo are acute or moderately rounded, while 
in hilli the sides of the coste are perpendicular to the wall of the corallum. 
1 Denkschrift d. Wiener Akad. d. Wissenschaft Mat. Naturhist. CL, 1868, Bd. 
XXVIII, Plate I. Fig. 1. Denkschrift d. Wiener Akad. d. Wissenschaft Mat. 
Naturhist. CL, 1874, Bd. XXXIII, pp. 20, 27, Plate XLIII. Figs. 8-7. 
2 In this volume, page 139, Reuss calls this species Trochosmilia profunda, but 
later, in Vol. XXXIII. of the same series of publications, he shows that he had at 
first confused two species under the name profunda, and separates the forms into 
T. profunda and T. acutimargo, Plate I. Fig. 1, Vol. XXVIII, taking the latter 
designation. i 
