46 



Report of the State Geologist. 



been interrupted at various stages of acquirement, epheby 

 being sometimes hastened, sometimes delayed. It will be 

 understood that in terming this form normal we do not assume 

 the form thus characterized as a center of departure for 

 variations, but merely as the most commanding expression 

 of the Intumescens type in these faunas. It is the 

 Patterson i subtype. 



This expression of the species is wide-spread; although 

 it has not been observed in the Styliola limestone or 

 introductory appearance of the fauna, it is found usually 

 with indifferent preservation, scattered abundantly through 

 the greenish and grey shales of the Naples beds, not infre- 

 quently finely preserved in the caleareo-argillaceous concre- 

 tions of these beds, occasionally in full size as barite 

 replacements in concretionary masses. Many fine specimens 

 have been taken from the red and green kramenzel or 

 Figure i. Manticoceras concretionary stratum which, inmy previous papers, has been 



Pattersoni, natural size. p n i •i i , i ,/ • , • l ii rri • 



vertical section through fully described as the "goniatite concretionary layer. JLnis 

 tions, U shcwing the^vlria- is a stratum best developed in the northern part of the town 



tionain whorl-section and « -» T i i • . ■> -i r>n l ill ^ 



the gradual increase with oi JNaples whence it has been followed eastward through 



final decrease of overlap p , i j 1 • p it , 



in the whoris some ot the towiislnps oi Y ates count}'. 



The form continued its existence while the sediments of this age gradually 

 became more arenaceous, and its impressions are frequently observed on the 

 sandy flags intercalated among the lower shales of the group. In the upper 

 beds the species is rare. It has been stated above that the shells 

 which have been described as Gon. simiosus and (ion. {Clymetiid) 

 Nundaia are all examples of Mantic. Pattersoni usually of large, gerontic size, 

 such modifications in septation and umbilication as they present being wholly 

 due to maceration before, destruction during, or distortion since, fossilization.* 



The specimens to which these names have been authoritatively applied 

 and which conform in their general aspect to the illustrations and descriptions, 

 have the walls of the shell worn away, the septa also more or less abraded 

 along their lateral portions so that all lobes and saddles are diminished as the 

 section which they expose to the surface is taken near or even along the 

 center of the septum where the convexity and concavity is in all parts greatly 



* Gon. sinuosus was described by Prof. Hall in 1843 (Kept. Qeol. Fourth Dist., p. 243, fig. 6) ; Gon. (Clymeniu) Xunrfaia 

 by Hai.i,, in 1874 (Descr. New Species of Gouiatitidse, p. 3, the same being reprinted in the Twenty-seventh Ann. Kept. N. Y. 

 State Mus , p. 134, 1875). Both forms were floured under their respective names in the Illustrations of Devonian Fossils 

 (pis. 70 and 72, 1876,) but in 1879 (Pal. N. Y., vol. v, pt. 2, p. 460), the two are regarded as representing one species, Gon- 

 sinuosm, which is illustrated on plates lxx, (figs. 13-lo), lxxii (fig. 11), lxxiv (fig. 11). The localities from which the species, 

 is cited are in the sandstoaeB of the Portage group, in Livingston, Genesee, Chautauqua, Cortland and Tioga counties. 



