TABLE OF CONTENTS 



Page 



Introduction 1 



Explanation of measurements and abbreviations used 1 



The spider crabs or Oxyrhj-ncha of America 5 



Analogous species on opposite sides of the continent 7 



Species on both sides of the continent 8 



Systematic discussion ' 9 



Keys to subtribes, superfamilies, families, and subfamilies 9 



Superfamily Oxyrhyncha 10 



Family Majidae 10 



Subfamily Inachinae 11 



Genus Stenorynchus 13 



Stenorynchus seticornis 13 



debilis IS 



Genus Metoporhaphis 19 



Metoporhaphis calcarata 21 



Genus Anomalothir 23 



Anomalothir f urcillatus 24 



frontalis 25 



Genus Achaeopsis 2% 



Achaeopsis thomsoni 29 



Genus Podochela 31 



Podochela riisei 33 



sidneyi 39 



algicola 41 



vestita 42 



margaritaria 43 



macrodera 44 



grossipes 45 



gracilipes 47 



hemphillii 49 



cur virostris 50 



lamelligera 52 



barbarensis 54 



latimanus 56 



lobif rons 57 



Genus Inachoides 59 



Inachoides microrhynchus 60 



laevis 61 



Genus Anasimus 64 



Anasimus f ugax 64 



latus 65 



Genus Erileptus 68 



Erileptus spinosus 68 



Genus Oregonia 70 



Oregonia gracilis 71 



bif urea 79 



III 



