200 S. S. Buckman—On Jurassic Ammonites. 
two species should not be made out of the Pea-grit forms, on 
account of both the minute tubuli and the larger type occurring in 
the same spherule. For the present, however, I do not see my way 
clear, as it may be that the two forms are associated together in 
the same spherule. 
As to what known organisms Girvanella should he referred is 
a matter which seems to me to be one of considerable difficulty. 
Professor Nicholson and Mr. R. Etheridge, jun., referred it to the 
Rhizopoda and regarded it as related to the arenaceous Foraminifera. 
From this view Professor Nicholson, in his later communication, 
sees no reason to depart (loc. cit. p. 23). 
Girvanella pisolitica (new species), Plate VI. Figs. 10 and 11. 
This species occurs in the form of flattened spherules varying 
in size from 1 to 3%; of an inch in greatest diameter (Fig. 8, 
Plate VI.). In the centre of each spherule there is a nucleus 
which is surrounded by calcareous tubuli (Figs. 10 and 11) with 
well-defined walls, and averaging about ;3> of an inch in diameter, 
though some are smaller. In some instances, more especially in 
the larger spherules, the tubes bend and twist about in a truly 
vermiform manner, often assuming the form of a flattened coil. 
It differs from G. problematica inasmuch as the tubes do not 
occur in aggregations, and are more concentric around the nucleus. 
The tubes are also branching and are larger than those of G. 
problematica. 
DESCRIPTION OF PLATE VI. Figs. 8—11. 
Fic. 8. Spherules of Girvanella pisolitica from the Pea-grit near the base of the 
Inferior Oolite, Cheltenham. Natural size. ; 
Hae, Portion of Girvanella problematica from a Coralline Oolite spherule. x 68 
iam. 
Fie. 10. Gérvanella pisolitica, shown in section, from near the base of the Inferior 
Oolite near Cheltenham. x 40 diam. (not 50 diam. as erroneously marked on 
the plate). 
Fie. 11. Another spherule of Girvanella pisolitica from the Pea-grit near Chelten- 
ham. x 380diam. Shows a joint of a Crinoid as a nucleus. 
IJI.—On Jurassic AMMONITES. 
By S. S. Buckman, F.G.S. 
AMMONITES SERPENTINUS (Reinecke), and Ammonires STRANGE WAYSI, 
Sowerby. 
N a former communication (Grou. Mag. Dee. III. Vol. IV. No. 9, 
p- 896, 1887), when pointing out how Reinecke’s Amm. serpen- 
tinus had been misunderstood, I gave as a synonym, but with a 
query, Sowerby’s Amm. Strangewaysit. As I have, since then, 
examined the type-specimen of the latter species contained in the 
collection of the Natural History Museum, and as Mr. E. Walford 
kindly forwarded me for my determination a capital specimen from 
Byfield, I have been able to satisfactorily settle the identity of these 
forms. Except being evolute carinate Ammonites, the two species 
have hardly a feature in common. 
