OOLITIC AMMONITES. 
79 
The only specimen in the collection is a fragment of the 
whorl represented two-thirds of the real size. 
AMMONITES GUTTATUS.-S<rac7t<^, MSS. 
Plate 13, fig*. 2. 
A. guttatus, Blanford, Spiti fossils in Journ. As. Soc., Bengal, 1863. 
A. testa discoidea, late umbilicata, tuberculato-costata. Anfracti- 
bus sub-depressiSj ad marginem late rotundatis, costatis, apud umbi- 
licum tuberculis 19 compressis coronatis, intervallim 3-4 sulcis pro. 
fundis notatis. Apertura semiorbiculari. 
Diameter, circa 3 in. 
The above description of this Ammonite is taken, in part 
only, from the specimen in Colonel Strachey’s collection, which 
is an imperfect external cast of one side of a shell. There 
can, however, be little doubt that the species is identical 
with one found at Spiti by Dr. Gerard, and figured in the 
Journal of the Asiatic Society of Bengal. The latter is 
the authority for the description of the general form of 
the shell. The restoration herewith given at Plate 13, fig. 2, 
is consequently erroneous, the diameter of the whorls being 
probably at least half as much again as they are repre¬ 
sented, while from each tubercle springs a bundle of 4 or 5 
ribs, which cross the ventral region with a slight convex curve 
towards the mouth. Sufficient is seen of a portion of the 
impression of the outer whorl of Colonel Strachey’s specimen 
to warrant these inferences. A . guttatus is nearly allied 
to A. coronatus , Brug, but has a wider umbilicus. 
AMMONITES BIPLEX.—Sowerbi/. 
Plate 11, fig. 1, Plate 12, fig. 1. 
A. biplex, Sow., Min. Conch., Plate 293, f. 1,2. 
„ „ Blanf., Spiti fossils, in Journ. As. Soc., Bengal. 
Two specimens of this Ammonite occur in the collection, 
together with some impressions of the shell on black siliceous 
