Clarke — The Naples Fauna. 



89 



The whole aspect of the most advanced condition of the suture, is that 

 of relative immaturity, which endorses the general expression of the shell in 

 other respects mentioned. 



Locality. All specimens observed are from a ravine at Java village, 

 Wyoming county, N. Y. 



Among the more abundant goniatites of the Portage fauna are discoidal, 

 widely umbilicated shells which have usually been permitted to pass with the 

 designation "Goniatites complantus, Hall." We shall presently examine the 

 value of this appellation. These shells, in their adult characters, afford a 

 remarkable series of progressional phases from a simple type of suture like 

 that of Manticoceras to the most complicated form known in the Devonian 

 faunas, Beloceras, represented typically by the German upper Devonian shell, 

 Goh. muUilobatus, Beyrich. Forms representing the precise phases about to 

 be described have not, we believe, been elsewhere recorded. Indicatory as 

 they are, not of the completed development of the typical Beloceras it is 

 with some hesitation that any are referred to that genus. Beloceras mmlti- 

 Iphatwm is a flat, umbilicated shell, like the species under consideration in all 

 external characters and general aspect. Its suture, however, becomes highly 

 serrated even at early growth stages, as shown by Branco,* and at maturity 

 it consists of not less than fourteen lobes and saddles on each lateral slope, all 

 being acutely angled except the minor auxiliary curves.f The Sandbergeks' 

 figures of the suture in this species show that there is an immature growth- 

 stage in which the lobation of the septum corresponds with the adult 

 condition in one of our species, Gon. iynx, where the lobes and saddles 

 are but five in number, but the Naples species do not pass this degree 

 of lobation, nor do they ever attain the large size of JBeloc. multiloba- 

 fa in. Again, the Naples species, Gon. iynx with its five lobes, and Gon. 

 Lutheri, with but two acute lobes and saddles, are so nearly alike in all 

 respects except the form of the suture, as to be indistinguishable from 

 each other when that feature is obscured. Their mature conditions when 

 the shells are of equal size and of the same number of volutions, seem 

 not to stand in immediate successive phyletic relation, for so far as our 

 evidence goes there is no immature condition of (ran. iynx whose suture 

 exactly reproduces the adult form of that of Gon. Lutheri. The small dorsal 

 or sublateral auxiliary lobes of Gon. iynx are developed early and while the 

 principal lobes and saddles are in an obtuse condition ; thus in the rapid stride 



* Palaeontographica. xxvii, pis. vi, vii. 



t See Sandbsrger, Verstein. d. Rhein. Syst. in Nassau, pi. lv, flg. 3f. and p. 56, fig. 7. 



