THIRD, OB V'EBMK ERAS BRAN< 11 



Caloceras Ortoni, ii>mi 



Cat \\ ll ■ 



Loea:. 



shell is fully preserved in the only specimen found. This form resembles 



' ■ ■ \ rtheastern Alps more than any other species, Thei 



the same closely crowded fold-like bent pite without genicular, similar narrow 



channels with depressed lateral ridges and sunken keel, and Bimilar gibbous form 



of whorl, flattened abdomen, and discoidal aspect. The young were Btudied in 



The earlier Btages are excessively broad and Bmooth for three whorls. 



tubercular folds appear on the latter pari of the third «>r first quarter of the 



near tin- abdomen. These gradually lengthen, but remain verj 



trated by wide depressions during the entire fourth whorl. There 



are about twenty pilsa <>n this whorl including the tubercles, thirty-five <>n the 



fifth, and perhaps fifty-eighl on the sixth. 



1 1 - Dally a pilation is wanting, indicating the former presence of a nunc or 

 iperture, but these, though numerous, are not at regular intervals. 

 rionally pilations are doubled, but these are not shown in the figure. 



th whorl there are about eighty pilsa, and on the latter part of 



this volution they begin to lose their prominence, and <>n the latter pari of the 



eighth they suddenly degenerate into coarse crowded striatums. These changes 



companied l>y a very Blight elevation of the abdomen, broadening and 



shallowing of the channels, while the keel appears to be more prominent 



I ing whorls are similar to those of Cat I- The keel appeal 



a low, broad ridge on the first quarter of the Bixth volution, but the channels 



•. in the section examined, until first quarter of seventh volution. 



They are at this time very -hallow and narrow, and the keel is also depressed and 



but on the eighth volution both these parts become more fully 



Effort was made by removing the shell to Bee tin- sutures, Imt not 



i txiliary p the sutures arc inclined posteriorly, but 



I Milled. 



' v, ihner, 1 is the geographical equiv- 



alent of the broad, depressed-whorled Cat. 1 i of the Middle 



Europ Wanner considers that LoH ma) be the nearest affine 



/ - his guidi re of the latter. This means 



only the compn . which we have noted in the fust 



I •■cine depressed whorl* of fa ■• dy similar 



' i . figured on Plate X \ III . 



and this u very Ilk' I by Wiihner, an old specimen ol 



1 liv < i Umbel i i ' i W ah .' 



exhibil whorls in the young, and acquires the deep channel* 



well tb, and thi 



