PLATE LXXVII. 



Orthockras luxum. 



Page 241. 

 See Plates 35, 76, 78, 78 B, 81, 112. 



Fig. 1. An individual of this species, preserving a large portion of the chamber of habitation, and twenty- 

 thi-ee of the ordinary chambei-s. Schoharie, iV. Y. 



Fig. 2. A small individual showing the concave walls of th-^ chambers in the lower part of the figure. The 

 organic deposit is not represented. Scltoharie, iV. Y. 



Fig. 3. Ventral view of a spiHiimen with the apical portion much compi-essed. The organic deposit imli. 

 eating the ventral side is not shown in the figure. Clarkimille, j!f. T. 



Fig. 4. Fragment showing the siphuncle exposed by weathering, and the longitudinal plications extending 

 along the separate beails. Schoharie, iV. Y. 



Rg. 5. A septate fragment showing the walls of the chambera broken away, except a few of the upper ones, 

 and the organic deposit nearly filling the intereeptal spaces. This featui-e is more satisfactorily 

 shown in another specimen, repi-esented in figure 13, plate 81. Schoharie, N'. Y. 



Fig. 6. Ventral side of the apical portion of an individual, retaining much of its normal form. Tlie longi- 

 tudinal carina on the ventrum is not represented. 



Fig. 7. Lateral view of a specimen, showing the dislocation and obliquity of the chambei-s caused by com- 

 pression. 



Fig. 8. Longitudinal section, showing the convexity of the septa and the depth of the chambers. The ele- 

 ments of the siphuncle are more fully represented in figure 3, plate 78 B. 



