OEISKANY FAUNA OF BECBAFT MOUNTArtT 15 



Odontocephalus selenurus; Spirifer varicosus; Atrypa 

 reticularis, large and rotund; Leptaena rhoraboidalis ; Strep, 

 torhynchus pandora; Chonopliyllura; Zaphrentis; Favo- 

 sites, branching; Stroma topor a or Fistulipora, incrusting. 

 With the evidence before us then, we have no hesitation in concluding that 

 the succession of the upper Helderberg beds from the top of the Oriskany 

 sandstone upward is fairly complete, representing the Esopus slate, the 

 Schoharie grit, the non-chert-bearing Onondaga limestone and characteristic 

 " Corniferous " limestone. 



Chapter 2 



DESCEIPTION OF TPIE FAUNA 



TRILOBITES 



Dalmanites (Synphoria) stemmatus sp. nov, 



Plate 1, flg. 6-16 ; plate 3, Sg. 1, 3 



1892. Dalma/nitea, sp. nov. A, Clarke, op. cit. p. 412 



Species attaining considerable size. Cephalon convex, abruptly slop- 

 ing to the genal margins. Genal extremities somewhat produced but rela- 

 tively short and terminating in broad, obtuse angles. Dorsal furrow 

 deep except at the junction of the glabellar lobes with the palpebral 

 lobe, where it becomes shallow and very much elevated. Frontal lobe 

 of glabella large, rounded in front, slightly elongated at the axial 

 extremity but not projecting beyond the frontal border or facial suture. 

 First lateral furrows long, deep and oblique, extending nearly three 

 fourths the diameter of the lobe. Glabellar surface behind the frontal 

 lobe slightly if at all depressed medially. Second and third lobes 

 wholly confluent at their extremities, often but a remnant of the second 

 lateral furrows remaining. Together these coalesced lobes have a sub- 

 triangular or subclavate outline and are convex and elevated at their 

 distal extremities, rising above the full hight of the glabella and almost to 

 the hight of the palpebral lobe. The third lobes are small and narrow, 



