WAAGEN : CAEBONIFEKOTJS AMMONITES, &C. 3 



It is not without some doubt that I refer the thin-bedded marly 

 calcareous series with Cephalopods to the carboniferous period^ though 

 it seems certain that AtJii/ris Roissi/i, L'Ev., Athjris mUilita, Hall, 

 ProducUis costatus, Sow., Prodiictus longispinus, Sow., and Produdus 

 Ewnloldtii, Orb., have not as yet been stated to occur in any other but 

 carboniferous beds. However, that is not the case with Stroplialosia 

 Morrisiana, King, which is one of the most characteristic fossils of the 

 Permian period. Besides that I have collected several Terehraiula, which 

 very much resemble Terehr. elongata, Schloth. Thus, we may assign 

 to the bed, in which the Cephalopoda occur, at least a certain affinity to 

 the Permian formation, and may not be very wrong in presuming that it 

 is situated at the limits between the Carboniferous and Permian period. 

 Further examiaation of the fossils will probably show which of the 

 affinities is greater, — that to the former, or that to the latter, formation, 



Phylloceeas Oldhami, Waagen, n. sp. 

 PI. I, Figs. 1, \a. 



The general form of the shell is somewhat flattened, lenticular, the 

 siphonal side is broadly rounded, the umbiUeus small. The whorls are 

 very involute, so much so that two-thirds of the outer whorl overlap the 

 preceding one ; the shell increases, therefore, very slowly both in thick- 

 ness and in diameter, a peculiarity which it has in common with most 

 of the Arcestes. The shell is, on the last circuit, provided with six 

 contractions, which begin at the umbilical margin, go fi-om there a 

 short distance straight and radial, turn then backwards and pass over 

 the siphonal side again with a slight btod towards the front. They are 

 not very deep, and on the outer whorls, near the siphonal region, are 

 barely perceptible. The umbilicus is small, deep, and with perpendi- 

 cular walls. 



The most characteristic distinction consists in the lobes. They ex- 

 hibit a general form, very much like that known in some monophyllie 



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