4 WAAGEN : CAUBONIFEEOUS AMMONITES, &C. 



PJir/llocerata, but the number of lobes is mucla greater than in any 

 otber known form, and their position quite different. I count fifteen 

 lobes on each side from the siphonal to the sutural lobe, all about equal 

 in shape, the first one, next to the siphonal lobe, being the largest, and 

 from there they gradually diminish in size. The first seven lobes termi- 

 nate with three priacipal fingers, the next three with two, the other five 

 are simply pointed. However, the sub-divisions of the single lobes are 

 very variable in shape. The siphonal lobe is broad, with two thick 

 arms directed towards the first lateral, and one long dentated branch 

 hanging down along the sipho. The saddles are very simple, each of 

 them terminating with one broad rounded phyllum, diminishing in size 

 towards the umbiUcus. The strangest point of all is the position of the 

 lobes, which in each series form a parabolical curve with two very un- 

 equal branches, the summit of the curve lying near the umbilical mar- 

 gin, whilst the branch proceeding to the siphonal periphery is much 

 longer than that descending to the umbilicus. This pecuhar arrange- 

 ment explains the excessive number of lobes, their course being one-and- 

 two-thirds longer than that lying along the radius of the spiral, in 

 which direction they are arranged in other known Ammonites. In these, 

 also, the longitudinal axis of each single lobe is very nearly parallel to 

 the involution of the shell, while in the present new species the axis of 

 the lobes forms a large angle with the involution. 



This arrangement of the lobes gives such a strange and extraordi- 

 nary aspect to the whole shell that I greatly hesitated to assign the 

 species to any of the existing genera of Ammonites. But yet, this 

 point alone seems not sufiicient to justify the creation of a new genus ; 

 and as other monophyUic forms, like PJii/U. Jarhas, Miinst., or saniali- 

 num, Mojs., were without any doubt united with Suess's genus, it seems 

 1)est, also, with the species just described not to deviate from this rule 

 until the length of the body-chamber and the shape of the aperture 

 become known. 



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