NO. 10 CAMBRIAN FOSSILS, 4TII CONTRIBUTION RESSER 23 



It will be observed that Cobbold's generic description of Stcnothcca 

 agrees in every detail with that of Watsouella Grabau. The illustra- 

 tions also agree ; therefore WatsoncUa must be regarded as a synonvm 

 of Stenotheca. 



All known species of Stcnothcca are confined to the Atlantic 

 province. 



Genotype. — S. cornucopia Salter. 



The following are regarded as valid species of Stcnothcca: 



S. angiista Cobbold 6". hicksiana Matthew 



5. conceit trica Matthew S. lata Cobbold 



S. cornu Wiman S. nasuta Matthew 



■S". cornucopia Salter 6". radiata Matthew 

 5". croshyi (Grabau) 



Species formerly referred to Stenotheca are given, together with 

 their synonyms. 



5". abrupta ? Cobbold = Helcionella cobboldi 



S. abrupta Grabau and Shimer.= i^. grabaui 



S. abrupta Shaler and Foerste = H. abrupta 



S. (Paniwrplwrclla) acadica Matthew = Paruwrpliorclla acadica 



S. clurius Walcott = Helcionella ? clurius 



S. curvirostra Grabau =: H. alia 



S. curvirostra Shaler and Foerste = //. curvirostra 



^ , , T,r 1 (Stenothccoides elongata 



o. elongata Walcott =:■{ r- , , , ■ 

 (_5. labradonca 



S. levis Grabau = Helcionella striata 



S. pauper Billings =: H. pauper 



S. pauper Grabau ^ H. recurva 



S. rugosa Billings ^ H. rngosa 



H. curticei 



H. fordi 



H. zvalcotti 



H. halli 



^Stenothccoides froyensis 

 S. rugosa Sears =^ Helcionella abrupta 

 S. rugosa Tate^^H. tatei 



S. ? rugosa acntacosta Walcott = H. acutacosta 

 S. rugosa aspera Noetiing =^ Pseudotheca zvaageni 

 S. rugosa erecta Walcott = Helcionella erecta 

 S. rugosa chinensis Walcott := H. chinoisis 

 S. ? rugosa levis Walcott ^ H. levis 



S. rugosa orientalis Walcott = H. oricntalis , 



S. rugosa pauper Shaler and Foerste ^ H. foerstei 

 S. rugosa paupera Walcott = H. pauper 

 S. simplex Walcott ■= H. ? simplex 

 S. triangularis Matthew := H . trianiiularis 

 S. wheeleri Walcott = H. zvheeleri 



S. rugosa Walcott ^^ 



