CEPHALOPODA OF THE OKETAOEOUS MARLS. 281 



ally seen. Very young- specimens often present a long slender extremity. 

 On the ventral side, the slit extends fully one-third of the length of the 

 shell, where the walls of the upper portion are preserved to near their full 

 length, which is seldom the case; its width in the lower half often being 

 little more than the thickness of heavy writing paper. The flattening of this 

 side of the stylet commences near the base of the slit and extends almost 

 to the lower extremity of the guard. On the dorsal side there is a raised 

 elongate lanceolate area, which is narrow and prominently angular in the 

 upper part of the body, but is flattened or simply depressed convex on the 

 surface and gradually widens below the base of the slit so as to become 

 from half the entire width of the shell to almost its equal in width, but 

 produces a slight angularity on this side throughout the entire length. The 

 entire surface is usually much roughened when not worn, the roughening 

 being greatest on the ventral side, while laterally this roughening produces 

 vascular lines running obliquely backward in crossing from the ventral to 

 the dorsal surfaces, and on the raised lanceolate area of the dorsal surface 

 the markings are finer and arranged so as to produce longitudinal lines, or 

 interrupted striae. 



I have not, in any of the New Jersey specimens, no matter how well 

 preserved, been able to see anything of the rostrum or dorsal extension of 

 the upper portion. 



The phragmocone is seldom seen showing the lines of septa, and when 

 seen they appear to be only external or marginal. Among the few bearing 

 the lines which I have examined none have shown the septa extending 

 across. This body is rather abruptly obconical, and is just a little ovate in 

 transverse section, one side being a very little angular and with a raised, 

 rounded, longitudinal ridge, corresponding to the angularity of the solid 

 side of the alveola of the stylet or guard, the side corresponding to the 

 fissure of the guard being regularly curved, as is the inside of the cavity 

 itself The lines of septa are very numerous and closely arranged near the 

 pointed end, but gradually and regularly increase in distance from each 

 other, so that where the diameter of the cone reaches five-eighths of an inch, 

 the septa are fully a twelfth of an inch apart. In their direction across the 

 cone they are nearly straight, except on the angularity, where they are 

 slightly advanced. The position of the siphuncle I have not observed. 



