De ee a 
1S) 
THIRD, OR VERMICERAN BRANCH. 15 
Caloceras Ortoni, Hyarr. 
Caloceras Ortoni, Hyatt, Proc. Bost. Soc. Nat. Hist., XVII, p. 867. 
Locality. —Tingo, near Chacapoyas, Northern Peru. 
The shell is fully preserved in the only specimen found. This form resembles 
Cal. salinarium of the Northeastern Alps more than any other species. There are 
the same closely crowded fold-like bent pile without genicule, similar narrow 
channels with depressed lateral ridges and sunken keel, and similar gibbous form 
of whorl, flattened abdomen, and discoidal aspect. The young were studied in 
section. The earlier stages are excessively broad and smooth for three whorls. 
Coarse tubercular folds appear on the latter part of the third or first quarter of the 
fourth volution, near the abdomen. These gradually lengthen, but remain very 
broad folds separated by wide depressions during the entire fourth whorl. There 
are about twenty pile on this whorl including the tubercles, thirty-five on the 
fifth, and perhaps fifty-eight on the sixth, 
Occasionally a pilation is wanting, indicating the former presence of a more or 
less constricted aperture, but these, though numerous, are not at regular intervals. 
Occasionally pilations are doubled, but these are not shown in the figure. 
On the seventh whorl there are about eighty pile, and on the latter part of 
this volution they begin to lose their prominence, and on the latter part of the 
eighth they suddenly degenerate into coarse crowded striations. These changes 
are accompanied by a very slight elevation of the abdomen, broadening and 
shallowing of the channels, while the keel appears to be more prominent. 
The young whorls are similar to those of Cal. Liasicum. The keel appears as 
a low, broad ridge on the first quarter of the sixth volution, but the channels 
were not present, in the section examined, until first quarter of seventh volution. 
They are at this time very shallow and narrow, and the keel is also depressed and 
not very broad, but on the eighth volution both these parts become more fully 
developed. Effort was made by removing the shell to see the sutures, but not 
with success. The auxiliary portions of the sutures are inclined posteriorly, but 
otherwise nothing was satisfactorily ascertained. 
Cul. (Ariet. proaries var.) latecarinatum, Wibner,’ is the geographical equiv- 
alent of the broad, depressed-whorled varieties of Cal. Lnasicum of the Middle 
European province. Wiihner considers that Loki may be the nearest affine 
to Cal. Liasicum, taking as his guide Reynés’s figure of the latter. This means 
only the compressed varieties of this species, which we have noted in the first 
subseries. The extreme depressed whorls of Jatecarinatum are closely similar 
to the next form of the subseries Ca/. (_Aviet.) salinarium, figured on Plate XVIIL., 
and this is very likely, as supposed by Wahner, an old specimen of salinarius, 
though described by Giimbel as Amm. euceras. Cal. (Ariet.) centauroides, Wih., 
exhibits very stout whorls in the young, and acquires the deep channels and 
well developed keel at a late stage of growth, and these continue to be better 
1 Mojsis. et Neum., Beitr., V. pl. xvi. = Tbid., Viepl: xxiv. 
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