INDEX TO VOLUME I. 33 1 



PAGES 



Polypora subniarginata 1G7 



Polypora whitei 170 



Productus cora d'Orbigny 166, 168, 170, 172, 176, 177, 179, 180 



Productus costatus Sowerby ? de Koninck 166, 168, 172 



Productus longispinus Sowerby 166, 168, 170, 172, 179, 180 



Productus nebraskensis Owen 165, 166, 168, 170, 172, 174, 177, 179, 180 



Productus pertenuis Meek 165, 166, 168, 170, 172 



Productus punctatus ( Martin ) Morton 166, 168, 172, 176 



Productus semireticulatus ( Martin) d'Orbigny, 166, 168, 170, 172, 177, 179, 180 



Productus symmetrica 170, 179 



Projective transformations and their continuous groups 115 



Protostega ? 247 



? Pseudomonotis hawni equistriata Beede var. ? 173, 175, 176, 178 



Pseudomonotis kaneasensis 176, 178 



Pseudomonotis robusta 176 



Psilopus bellulus 93 



Psilopus caudatulus 94. 



Psilopus chrysoprasius 93 



Psilopus insularis 94 



Psilopus jucundus 94 



Pteria longa (Geinitz ) 173 



Pugnax utah (Marcou ) Hall and Clarke 166, 170, 173, 179, 180 



Quadric surface, On collineations which leave invariant a 281 



Quartic monoids, classification of 311 



Real subgroup of He 139 



Reptiles, Notes on Some New or Little-known Extinct 247 



Rest stage 225 



Reticulata perplexa 165, 166, 168, 171 



Rhabdomeson americana 181 



Rhipidonella pecosi 179, 180 



Rhombopora lepidodendroides Meek 164, 167, 172, 179, 181 



Robertson, cited 36 



Rogers, Austin F., Some New American Species of Cyclus from the Coal 

 Measures 269 



Sarcionus lineatus 82 



Scaphiocrinus washburni Beede 172 



Schizodus rossicus 168 



Schizodus alpina ( Hall ) Keyes 173 



Schizodus circulus Worthen 173 



Schizodus curtiformis 168 



Schizodus curtus 168, 171 



Schizodus wheeleri (Swallow) Meek 173 



Scrolar lines 306 



Sedgwickia altirostrata , 176, 180 



Sedgwickia topekensis 175 



Seminula argentia (Shepard) Hall and Clarke 165, 166, 168, 171, 173, 



174, 176, 177, 179 

 Septopora biserialis 167, 179, 181 



