Permo-Carboniferous Ammonoids of the Glass Mountains 97 



on the last portion the sculpture seems to disappear entirely and the 

 shell appears entirely smooth, with faint undulated lines of growth. 



The body chamber is unknown. All the specimens are septate 

 throughout. 



The septa are near together and in the smaller whorls almost touch 

 each other in certain places. The suture (pi. IV, fig. 26, 36) follows 

 a straight line between the sipho and the umbilicus. In a specimen 

 with a diameter of 12 mm. the paralegoceran stage of the suture is 

 still visible in the lower half of the whorl, while in the largest portion 

 we find already the schistoceran stage. From here on, the suture does 

 not change materially, as is shown in our pi. IV, fig. 26, 36 ; one figure 

 representing a suture at a diameter of 26.0 mm. and another one at a 

 diameter of 45.0 mm. 



The siphonal lobe is divided into two branches by a high median 

 saddle. Each of the branches is broad and long, asymmetrical on ac- 

 count of the umbilical side being sinuous while the siphonal side shows 

 a simple curve ; the branch ends in a sharp point, and it is a little nar- 

 rower at the top than in the middle. The first lateral lobe is also asym- 

 metrical, the lateral convexity being higher on the siphonal than on the 

 umbilical side ; it is generally tongue-shaped, pointed, a little narrower 

 at the top than in the middle, and slightly shorter than the branches of 

 the siphonal lobe. The second lateral lobe is about as wide as the first 

 one and similarly shaped but considerably shorter. A small funnel- 

 shaped, pointed auxiliary lobe exists still on the lower part of the flank. 



The median saddle of the siphonal lobe is very high and slender, 

 broader at the base than at the top, where it is notched by an indenta- 

 tion; it is slightly constricted above the base. The saddles are all 

 spatulate, rounded above and slightly constricted (with exception of the 

 auxiliary saddle) . The external saddle is much higher than the median 

 saddle of the siphonal lobe and very narrow. The first lateral saddle 

 is a little lower than the external one and a little higher than the median 

 one of the siphonal lobe ; it is a little narrower than the external saddle. 

 The second lateral saddle is lower than the first one, but of about the 

 same width. In general it may be said that the length of the saddles 

 decreases very gradually from the external to the second lateral saddle. 

 An auxiliary saddle exists near the umbilical shoulder, but is completely 

 visible on the flank. It is considerably lower than the second lateral 



