298 



stages, 



see 



species. (For discussion of the iiiimature 

 Clarke's Naples Fauna. ) 



Found in the Naples shales of Big Sister and Farnum 

 creeks; and on the Lake Shore, near Angola. (Clarke. ) 



GoNiATiTES (Pkobeloceras*) lutheri. Chii'ke. (Fig. 

 233.) (Bull. IGth U. S. Geol. Surv., p. 50, PI. II. Clarke: 

 Naples Fauna, pp. 90-102. ) 



Distinguishing Characters. — "Shell widely umbilicated, 

 more so than any species with which it 

 is associated * * *. Septa numerous 

 and closely appressed " *; the sutures 

 are characterized by their acute lobes 

 and saddles: ventral saddle very small, 

 short, and very slightly rounded, the 

 two lateral lobes strong and acute; the 

 lateral saddle very strong and acute, 

 with its sides somewhat rounding; the 

 dorsal saddle well defined and rounded, 

 with a slight, sharp carina! lobe * * *; the septa are so 

 closely crowded together that they are very nearly ]»arallel 

 to each other except at the apices of the lateral saddles, 

 where the distance between them is some^^dlat greater than 



Fig. 233. O on iat i te x 

 lutheri. Showing sutures 

 (after Clarke). 



elsewhere; surface markings 



finely incised, equi- 



distant lines, curving gently forward as they near the dorsal 

 surface * *." (For a discussion of the immature stages, etc., 

 see Clarke's Naples Fauna. ) 



Found in the Goniatite concretions of the lowei* Naples 

 shale, at Sections 1 to 4. 



GoxiATiTES coMPLAXATUs. Hall. ( Fig. 234. ) ( Pal. X. Y., 

 Vol. v., Pt. II., p. 455, PI. LXX.) 



This species was originally described in the Report on the 

 Fourth Geological District, from a compressed S})ecimen 

 from the Naples shales of Cashaqua Creek. [Clymenia {?) 



♦Probeloeeras, Clarke, 1898, Naples Fauna, p. 90, has the following diagnostic characters, 

 differentiating it from other Goniatites : " Discoidal, laterally conipiesspil. ninhilicated 

 shells, with a narrow peripheral band, concave and with raised edges in immature stages, 

 convex in the adult. Suture with a single large and acutely-angled lateral saddle, and two 

 acute lobes : ventral and sub-lateral lobes rounded. Early stages show a gradual derivation 

 of the suture from a manticoceran outline by the sharpening of the principal saddle and 

 sub-lateral lobe. " 



