PART I.] 
Waagen : Ammonite-fauna of Kutck. 
95 
become compressed, the ribs flattened, and the body-chamber of a specimen of 60 m m. in 
diameter (about the largest size the species appears to attain) is nearly quite smooth. 
The section of Per. Martiusi is represented in the Ivutch Jura by nine determinable and 
at least four, as yet undeterminable, species, the latter being in our Museum only indicated by 
fragments, not sufficient for a reliable definition of the species. The better known species 
belonging to this section are: 
Perisphinctes spirorbis, Neum. (golden oolite, Keera hill). 
„ bracteatus, Neum. (same beds and locality). 
„ funatns, Opp. (same beds and locality'). 
„ paramorphus, Waagen, n. sp. (same beds and locality).' 
„ areieosta, Waagen, n. sp. (same beds and locality). 
„ curvieosta. Opp. (oolite of Dhosa; marl nodules, Goodjinseer; yellow 
marl rock, Jumara). 
„ euryptyclms, Neum. (hard yellow limestone, Keera hill). 
„ Pagri, Waagen, n. sp. (red iron rock, Kuntkote). 
„ Gudjinsirensis, Waagen, n. sp. (marl nodules, Goodjinseer). 
Perisphinctes paramorphus, Waagen, n. sp. A remarkable species, which nndero-oes 
great changes according to age. When quite young, the whorls are rounded and slightly 
involute, covered with strong, few, and dichotomous ribs; middle sized specimens have a 
slightly squarish section of the whorls, these being more involute and covered with moder¬ 
ately numerous, strong bipartite ribs. Growing only a little larger than 100 mm. in diameter 
the whorls become rather high oval with a narrowly rounded siphoual side, and the ribs 
disappear entirely; in this stage the species resembles large specimens of Per. spirorbis. 
Perisphinctes areieosta, Waagen, n. sp. An intermediate species between Per. auri- 
gerus, Opp., and cumcosta, Opp. The whorls are compressed like those in the former species, 
whilst the kind of ribbing agrees more with that of the latter. The largest size to which 
the species attains is about 60—70 mm. in diameter. In such specimens the body-chamber 
is but slightly ribbed and the lateral ribs are disconnected from those situated on the siphonal 
side. 
Perisphinctes Pagri, Waagen, n. sp. In its general form very nearly allied to Per. 
Orion, Opp., but with less strongly prominent and more numerous lateral ribs ; the ribs on 
the siphonal side are slightly turned backwards. 
Perisphinctes Gudjinsirensis, Waagen, n. sp. A species also belonging to the group 
of the Convoluti, but certainly one of the most extraordinary forms of the whole group. 
The whorls are very depressed and the umbilicus large. Young specimens are of the'usual 
habit, but fuller grown ones become provided with high, distant lateral ribs, which are 
divided into three flat branches on the depressed siphonal side, hull-grown specimens do 
not exceed a diameter of 100 m m. 
In connection with the few last mentioned forms I shall describe three species, which 
are as yet unknown from European jurassic formations, and which are, strictly speaking, more 
geologically than zoologically related to the former. They are: 
Perisphinctes frequens, Opp. (oolite of a valley, west of Soorka hill, together 
with Ithynch. myriacantha). 
„ denseptieatus, Waagen, n. sp. (same layer and locality). 
„ aberrans, Waagen, n. sp. (white marl rock, Keera hill). 
Perisphinctes denseptieatus, Waagen, n. sp. Very nearly allied to Per. frequens, Opp., 
but with a somewhat smaller umbilicus, higher whorls, and much finer lateral ribs, which 
