HILL: GEOLOGY OF JAMAICA. 245 
Turbinoseris cantabrigiensis, sp. nov. 
| Plate XL. Figs. 5-7. 
Form compressed, conical, attached by a very small pedicel, Measurements 
of two specimens give the following : — 
Height of Greater Diameter Lesser Diameter 
Corallum. of Calice. of Calice. 
a (figured type) 18.5 mm. 10.0 mm. 6 mm. 
Di aa 15.0 mm. 11.5 mm. 1 8 mm. 
The costa are very fine, crowded, not prominent and acute, alternating in 
size. The wall is synapticulate. There is no wall properly speaking, but the 
many synapticule near the peripheral ends of the septa serve as one. Of | 
course, perforations between the distal ends of the septa are frequent. The | 
septa are composed of ascending trabecule ; the fusion between them seems 
sometimes, but very rarely, incomplete, leaving pits or occasional perforations. 
The septa are very numerous, extremely thin, and very much crowded; not 
thickening at the centre. The type has between 80 and 90 septa; the other 
specimen, whose measurements are given above, has five ecmplete cycles, 
apparently 99 septa. Some septa of the higher cycles fuse by their edges to 
the sides of the members of the lower cycles. | Calice rather shallow. Strictly 
speaking, there is no columella, a few septa fuse loosely in the axial space. 
Locality. Near Cambridge, south of Montpelier, St. James Parish, Jamaica 
(R. T. Hill, collector). 
Remarks, The species above described is very close to Duncan’s Turbinoseris 
eocenica,t from the limestone of St. Bartholomew. I have been unable to see 
the types of the species from St. Bartholomew, as they are in Stockholm and 
Upsala, therefore the following comparison is based on the original description. 
There are two points of difference. The first is one of size. Duncan gives the 
size of T. eocenica, “ Height of full grown specimen 1 inch (= 25 mm.). 
Length of calice ;% inch (= 18 mm. ). Breadth $ inch (= 10 to 12.5 mm.” 2 A 
T. cocenica is a much larger species. Duncan states that there are five cycles 
of septa with some members of the sixth in the species ; therefore the septa in 
T. cantabrigiensis are necessarily more crowded. The second difference concerns 
the inner terminations of the septa. Duncan says that in T. eocenica the ends 
of the larger septa are swollen, and bound the axial space. As stated above in 
its description, T. cantabrigiensis does not have the ends of the larger septa so 
swollen. The two species are close, but appear distinct. Duncan’s Figure 12, 
Plate XXL, of the costal synapticule in T. coceenica would apply equally well 
to T. cantabrigiensis. 
1 Quart. Jour. Geol. Soc. London, 1873, Vol. XXIX. p. 558, Pl. XXI. Fig. 12. | 
? T have inserted the approximate equivalents in millimeters. 
