400 Mr. R. Bullen Newton on a Marine 
Dimensions. 
mm 
Diameter of calyx ...... ie wie SED 
Height of corallum......... . 40 
Locality. Bachain. 
Isastrea sp. 
This determination refers to a fairly large, rounded, and 
elevated corallum composed of unequally sized calyces, which 
in the neighbourhood of the margin frequently merge into 
one another and form elongate furrows, as characterizes the 
genus Latomeandra. There is, however, no epitheca in that 
genus, whilst the base of the Arabian fossil is distinctly 
furnished with a concentric epithecal growth. Through 
considerable erosion the septal characters are much obscured, 
so that until the specimen has been sectioned for micro- 
scopical examination it is impossible to give more details of 
1s structure. 
Dimensions. 
mm 
ELSI e RE ce pon Stel on bet 45 
DiamGtenPrrncca ous ce ct 90 
Locality. Al Hish. 
SPONGIA. 
Lymnorella sp. 
This fossil is of subspherical contour, with the basal region 
filled with matrix. ‘The surface-structure consists entirely of 
microscopical apertures, varying in size and presenting a 
minute vermicular type of structure such as is present in 
Lamaroux’s genus Lymnorea, now known as Lymunorella of 
Hinde, on account of the preoccupation of the first-mentioned 
name. ‘The genus is very characteristic of Jurassic rocks. 
Dimensions. 
mm, 
DeVere Aaya eres Oe bin 2 ee 
Diametorve) 00 Pani. ee 30 
Locality. Bachain. 
SUMMARY. 
The fossils herewith described represent the remnants of a 
marine fauna which thrived over a considerable area of what 
is now Arabia during the Jurassic period. ‘hey were chiefly 
obtained from Bachain, only two determinable specimens 
having been found at Hamar and two at Ashaira, while one 
a 
