62 



Report of the State Geologist. 



The form which was described by d'Archiac and de Yerneuil as Gon. 

 Buchi* approaches most nearly to the normal adult condition of MaiUio. 

 Pattersoni, though with somewhat more numerous septa on the final whorl. 



The specimens described by Tschernyschew f are also directly compara- 

 ble to the American forms in the attainment by growth of the narrow, sub- 

 carinate final whorl of fully matured shells from the broadly obcordate whorl 

 of earlier growth. 



Distribution of Manticoceras Pattersoni. 



Portagi group. The species occurs in notable abundance in a layer of 

 red and green kramenzel or nodular silico-argillaceous limestone lying about 

 200 feet above the top of the Genesee shales in the Naples section. The 

 rock is best developed in Parrish gully, on the east side of the Naples valley, 

 and appears at various points on the west side. It has been traced by Mr. D. 

 D. Luther as far eastward as Branchport, on Keuka lake ( Bellknap's gully, one 

 mile north of village), but is not continued far toward the west. The fossil 

 is found in the shales and on the surface of flags, but not often with favorable 

 preservation. Excellent specimens are often obtainable in the larger concre- 

 tions in which certain of the lower shale beds abound and is commonly seen 

 in the gullies and ravines on Conesus lake and eastward on Hemlock and 

 Honeoye lakes, in various sections throughout Livingston and Ontario 

 counties, in Genesee county at Attica, Sonyea and along Cashaqua creek. 



Qhemung (/roup. Specimens have been found in these rocks at Elmira, 

 Chemung county, and Pine Valley, Schuyler county. 



Manticoceras apprimatum, sp. nov. 



Plate VI, Figs. 27-l>9. 



We may best indicate the characters of this well denned form by com- 

 parison with allied species. The shell appears to be of uniformly small size 

 at epheby, and the final whorl has, in late growth stages, the Low, broad 

 lateral slope of M<///ti<: Pattersoni, though not becoming concave on the sides 

 as in the var. st/yUophihim. The umbilication is deep and narrow, closer than 

 in any other species, even more extreme than in Manila conpraotum. The 



* Desc. Foss. Older Deposits Rhenish Prov. p. -10, pi. xxvi, figs 1 a, b, 1842. This was shown by Kayser (Zeitsch. der 

 Deutsch. (ieol. Oesellsch. 1893, p. 040) to be synonymous with Gon. intumeacens and it was proposed by him to apply the 

 term Buchi to the French authors' Gon. Bnchi, var., in which he is followed by Hoi.zapfel (Palaeontographica N. F. viii. fi. 

 (xxviii), p. 243 [19]). The Sandbergkrs {op. cit.) and Clarke (Fauna des Iberg. Kalk.. p. 326, 1884) have adopted the older 

 term of Steininger, Gon. serrattis. 



I Fauna des mini, und ober. Dev. am Wegtabhange des Urals, pi. II, figs. 3, 5, 1887. 



