PART 4.] 
// aagen : Ammonite-fauna of Kutck. 
91 
Among the species of the genus Harpoceras, there is a single European form; all the 
other species are as yet known only from the Indian Jura. The species are : 
Harpoceras hecticum, Rein, (golden oolite, Keera hill). 
„ ignobile, Sow. (yellow limestone, Keera hill). 
„ crasscfalcatum, Waagen, n. up. (same layer and locality). 
„ Orientale, Orb. (rook indistinct, Keera hill). 
„ fornix, Sow. 
„ Nurrhaense, Waagen, n. sp. (iron nodule, Nurrha). 
Harpoceras crassfalcatum, Waagen, n. sp., resembles very much Harp, ignobile, 
Sow., bnt the whorls are depressed; the ribs much strongor, less numerous and much more 
irregular ; the species is also of smaller size, when adult. 
Harpoceras Nurrhatnse, Waagen, n. sp. Allied to Harp, lunula, Rein., but the ribs 
which cover the sides of the shell are much finer and sharper, and much more curved than 
in the last mentioned species. 
Peltoceras, Waagen, n. gen. This genus is, I consider, very closely allied to Aspido- 
ceras, Zitt., and possibly only a sub-genus of it. It is established tor the species which Zittel 
in his last volume on the Tithonian fauna has separated from his genus and united with Peri- 
spMnctes, but I think the relation between those forms believed to belong to Perisphinctes 
and Aspidoeeras perarmaturn, as he calls this Ammonite, are much closer than the relations 
between them and the true Perisphinctes, though contractions of tho whorls also occur in 
the former species. I am disposed to consider in this case the form of the lobes as the most 
important distinguishing character. Thus, for instance, in Amm. Arduennensis and Amm. 
perarmatus, the lobes are nearly identical in both species, the first lateral lobe being so much 
enlarged that the second lateral lobe becomes nearly obsolete; and as this form of lobes 
never occurs in the true Aspidoeeras (as Asp. iphicerum and others) nor in the true Peri- 
spMnctes (as there the auxiliary lobes have another position), I think it reasonable to separate 
those species with this particular shape of lobes under a distinct generic designation. The 
genus Peltoceras is, therefore, characterised by the particularly enlarged lateral lobe, a 
discoid, largely umbilicated shell; the whorls sometimes with contractions, always covered 
with strong straight ribs, which are sometimes provided with two or three rows of spines; 
siphonal side more or less flattened or even excavated, ribs crossing over or disappearing 
before they reach the siphonal part of the shell. Aperture more or less rectangular. 
Thus characterised, I believe, tho genus should include the groups of Pelt. Arduennense, 
transversarimn, perarmatum, hybonotum and a few other, less known, forms. The species 
of this genus occurring in the Kntch Jui’a are : 
Peltoceras athletu, l 1 hill, (gray marl nodule, N. of Goodjinseer). 
,, aegoceroides, Waagen u. sp. (brown oolite ol the Jooria hills). 
„ Arduennense, Orb. (same layer and locality), 
„ semiruyosuni, Waagen, n. sp. (brown oolite of Lodai and the Jooria 
hills'). 
„ bidens, Waagen, n. sp. (same layer and locality). 
„ perarmatum, Sow. (brown oolite of Lodai and Jooria, and doubtful 
from the red sandy iron rock of Kuutkote). 
,, monacanthus, Waagen, n. sp. (coarse yellow sand rock, Katvol range). 
Peltoceras aegoceroides, Waagen, u. sp. A very small species, with many thin some¬ 
what rounded whorls and numerous simple ribs which cross the siphonal side undivided; 
whorls barely touching each other. 
Peltoceras svinirugosttm, Waagen, n. sp. This species becomes extremely large, and in 
that form closely resembles Pelt, perarmatum, Sow. Young specimens, however, have almost 
