428 APPENDIX F. 
39 mm.; greatest width, 49 mm.; and of the preceding whorl: 
height, 30 mm.; ditto above preceding whorl, 24.5 mm.; greatest 
width, 28 mm. Only a small portion of the siphonal part of the 
suture-line can be made out. 
One fragment shows distinctly that the ribs are bidichotomous, 
dividing first into two branches, and then the posterior one again 
dividing into two branches, an ornamentation which Waagen notes 
in his description of Oppel’s Per. frequens. 
This species comes very near Per. frequens, which was described 
from Thibet by Oppel in 1865 and has been recognized by Waagen } 
as a rare species in the Oomia Group (= Tithonian) of the Kachh 
Jura. It also bears some resemblance to Quenstedt’s Ammonites 
polyplocus breviceps* from the White Jura ¥y, but it is a more inflated 
shell and the ribs divide nearer the periphery. Choffat figures? a 
specimen near to dreviceps Quenst., from the Montejunto beds in 
Portugal, and states that the form occurs also near Grenoble at the 
base of the zenzz/obatus-zone (Kimeridgian). 
3. Perisphinctes cf. denseplicatus, WAAGEN.! 
A crushed fragment exhibits a sculpture closely resembling that 
of the adult shell of Per. denscplicatus, Waagen, but it is so flat- 
tened that the original form of the whorl cannot be ascertained. In 
its crushed condition it is 37 mm. inheight. The primary ribs are 
about 4 mm. apart at the umbilical margin; each divides on the 
lateral area into three, and there is usually an intermediate rib. 
This fragment differs from those representing the preceding species 
in having finer and more numerous peripheral ribs. 
Waagen states that Per. denscplicatus is “the most common 
species of Ammonite in the Oomia Group” (= Tithonian). 
4. Perisphincies cf. torquatus, J. DE C. SOWERBY.® 
Another species is represented by two or possibly by three 
fragments. 
1 Pal. Indica, ser. ix., Jurassic Fauna of Kachh, ‘vol. i., p. zoo, Pl. XLIV., 
fiPS 1, 2a 3.8. LOS: 
2 Amm. Schwab. Jura, p. 944, Pl. CIII., fig. 2, 1887-8. 
3 Description de la Faune jurassique du Portugal. Céphalopodes, tre sér. 
Ammonites du Lusitanien de la contrée de Torres-Vedras, p. 53, Pl. XI., fig. 1., 
1893. 
4 Pal. Indica, ser. ix., Jurassic Fauna of Kachh, vol. i:, p. 201, Pl. XLVI., 
figs. 3a, b; Pl. LV., figs. 1a, b; 2 (especially the latter figures). 
5 Trans: Geol. Soc: [2], vol. v., Pl: LEXI: fig. 12,and expl:iot tig 
