OOLITIC AMMONITES. 
87 
AMMONITES STRIGILIS ,-niavf 
Journ. As. Soc. Beng., 18G3. 
A single specimen (cut in half and polished) of this Am¬ 
monite (without specified locality) only differs from the 
original Spiti specimen in its somewhat larger size. 
Diameter of shell, in. Diameter of outer whorl, ] ] in. 
AMMONITES ACUCINTUS.-«>W«-y, MSS. 
Plate 18, figs. 1 a-c; plate 19, fig. 4 (var. plate 18, fig. 2). 
A. testa dis coiilea, percompressa, complanatA, lcvigata, vcl striis 
rugisque falciformibus obsolete notata- Ventre sub-acuto, ad medium 
minutissime denticulato. Umbilico formte normalis angustissimo. 
Apertura obtuse sagittata. 
Diameter. 1-5 in. Spiral ratio.5 = 2 
Ditto of outer whorl ... 09 „ Immersion of whorls ... \ 
Thickness.04 „ Thickness: diameter ... | (approx.) 
A compressed discoid Ammonite, with flat sides and a 
very small umbilicus somewhat variable in diameter, but 
averaging in type specimens about one-tenth of that of the 
shell. The sides are ornamented with very numerous, regular 
falciform ribs, tolerably distinct in some specimens, nearly 
obsolete in others, and with a row of minute teeth forming 
an interrupted ventral ridge over the siphuncle. The ventral 
lobe is about two-thirds as long as the superior lateral, and 
rather broad. The other lobes sub-symmetrical and terminat¬ 
ing in three digitate branches. The saddles are symmetri¬ 
cally bifid. 
The figure of this species given in plate 18 is, in some 
respects, erroneous. The ribs in figs. 1 a should conform to 
the shape of the mouth, instead of being but slightly flexuous, 
and the periphery should be ornamented with minute sharp 
teeth, instead of crenulations. 
