17 Ithaca Group 17 



Section I, Fall Creek. 



This sedlion begins in the upper Portage sandstone at the foot 

 of Ithaca falls and ends at the outcrops in the bed of the 

 stream above Forest Home. This sedlion includes about 410 

 feet of strata. 



Station i. — The fauna of this station occurs in the Portage 

 flagstone and shale exposed at the foot of Ithaca falls. This is 

 the best locality known for collecting Spirifer Icevis, which is 

 the predominant species, and its associated fauna. 



The following is a list of species obtained from about three 

 feet of strata: Spirifer Icevis a*, Spathella typica c, Goniatites 

 sinuostis? r, Crayiia sp. r, Cyrtina hamiltonensis r, Lumdicardium 

 fragile a, Palceoneilo filosa a, Orthoceras pecator r, AviadopeHen 

 latUus var. ithacensis r, Goniatites discoideus c, Modiomorpha sub- 

 alata, Grammy sia subarcuata r, Taxocrinus ithacensis stems, Cho- 

 netes lepida a, Pleurotomaria capillaria r, Chonetes scitnla r, Gom- 

 phoceras tumidiitn r, Glyptocardia speciosa r, Coleohis tenuicinnus, 

 Nucida diffidens r, Mytilarca chemungensisf r, Leiorhynchus mesa- 

 costalis, Lingtda ligeaf r, Plumulina plumai^ia c, Aviadopefleti 

 rugtzstriatusf , Leda diversa. 



Station 2. — 135 feet above Station i. 



The rocks containing the fauna of the Ithaca shale are ex- 

 posed in the vertical cliffs of the falls, so that no representative 

 of it were obtained from this sedlion. 



At the summit of Ithaca falls the sandstone and silicious shale 

 contain the following species, indicating the initiation of the 

 Ithaca fauna: Produn:ella speciosa c, Spirifer ntesacostalis, Chonetes 

 setigera c, Amboccelia umbonata c, Pleurotomaria capillaria. Micro- 

 don tenuistriatus , Stiflopora nieeki c, Palceoneilo constrifla, AHin- 

 opteria boydi, Orthoceras bebryx var. cayuga, Modiom,orpha subalata 

 var. chemungensis c, Nucula corbidiformis . 



Station j. — From the foot of the cascade below the electric 

 light plant, the following species were colledled: Amboccelia um- 

 bonata a, Chonetes scitida, Rhynchonella exim,ia a, Palceoneilo flosa , 

 Leiorhynchus ntesacostalis, Gomphoceras tiimidum r, Modiomorpha 

 subalata var. chem,ung ensis , ABinopteria boydif r, Spirifer mesas- 

 trialis a, Microdon bellistriatus r, StiHopora meeki, Pleiirotomaria 

 capillaria r, Grammysia subarcuata? , Cyrtina hamiltonensis c, Pro- 



* The letter placed after a species refers to its abundance, — a, indicating 

 abundant, c, common and r, rare. 



