REPORT OF THE STATE PALEONTOLOGIST I9O3 33 1 



though not longer, for this reason probably amounting to as large 

 a proportion of the animal as in Proterocameroceras. 



Endosiphosheaths and endosiphofunicles. The endosiphosheaths 

 were, corresponding to the heavy weight they had to support, 

 rather stout membranes, reaching in some instances a thick- 

 ness of I mm. They are mostly well preserved, sometimes 

 closely crowded and separated by intervals not wider than .5mm 

 [see pi. 1 2, fig. 5] ; but in at least one instance they were also sepa- 

 rated by an open space of 5mm into which calcite crystals freely 

 project. Their sections are not evenly curved ellipses, but par- 

 take more of the nature of polygonal surfaces or are even 

 bounded by undulating lines. This is due to their being held in posi- 

 tion by guy ropes or funicles, which we will designate here as 

 '' endosiphofunicles." These are of the same nature as the endosi- 

 phosheaths and appear in sections as dark gray to black pillars of 

 organic carbonate of lime, often bounded by black lines. They 

 originated from membranous funicles, in which organic carbonate of 

 lime was deposited in similar manner as in the endosiphosheaths. 

 The sections [pl.ii, pi. 13, fig.3] show them well developed. Several 

 have been further enlarged to show their relation to the endosipho- 

 sheaths [see pi. 12]. 



If it were not for the outward curvature or angulation of the 

 endosiphosheaths [see pi. 12, fig.i, 2] at the points of connection with 

 the endosiphofunicles, and for the fact that the outer wall of the 

 siphuncles passes over these funicles [see pi. 12, fig.2 ; pi. 13, fig.5], 

 one might be inclined to consider them as worm tubes ; specially 

 where they appaar in such great numbers as in plate 11, figure 2. But 

 in this latter section it will be noticed that the greater number 

 pass only from the outer wall of the siphuncle to the first 

 endosiphosheath ; while but a smaller number — among these 

 the remarkable one in the upper right corner which bifurcates 

 three timos [see pi. 12, fig.i] — reach the inner endosiphosheath or the 

 endosiphocoleon. 



In looking over the series of sections, beginning with figure i 

 [pl.ii] we will readily notice that the number of endosiphofunicles 

 diminishes very rapidly with the shrinking of the endosiphosheaths 



