PALEONTOLOGY 



PLATE XVI. 



Page. 

 457 



Ptyciiockuas mkkkantm Wliitf 



Fk;. 1 . L.iti-ral view of a specimen preserving tbe curved extension of the smaller limb, and 



also showiii<; the oonimoiicemcnt of old age characters, in the closely arranged 



rings near the outer end of the larger limb, 

 l-'iii. v;. Diagram of a sei)tiMii from Jiiht within the bend of a similar specimen. Enlarged 



to two ilianiettTs. 



I'TYCimtKltA^i ClfA.'J.SUM Wliitf 4.'j9 



Fiti. ;{. Lateral view of the specimen described, natural size. 



Fuj. 1. Dorsal view of the same, showing the features of this part of the shell. 



Fi«. 5. Diagram of a septum from another individual, enlargtid to the same extent as Fig. 2. 



Fig. (5. Sectional diagram of the si>ecimen, showing the thickness of the shell. 



An< VLOCEKAS .IKN.VEVl Whitf 452 



l''iG. 7. Lateral view of a spccimi^n of tbe species, preserving an outer volution and parts 



of the inner smaller coil. 

 Fig. S. Dorsal view of the outer part of the same, showing the ranges of nodes, not exactly 



the sauu' (ui tbe opi)osite sides. 

 Fni. y. Diagram of a septum from near the liiiddle of the larger coil. Two diameters. 



See also PI. L"), Fig. 5. 



N AUTILfS DKKAYI Var. MOXTAN.EXSIS Mcck 



Fl<i. 10. ^■iew of the inner side of a specimen, showing the breadth of the shell and the 



distance of the septa. 

 Fio. 11. Lateral view of the same specimen, showing the rate of increase in the coils. The 



apjiarent umbilical jierforation ari.ses from the exfoliation of the shell. 



439 



II 



m 



