KESTUDY OF SOME BURGESS SHALE FOSSILS 



By George Evelyn Hutchinson 



Of Ihe Ostorn Zoological Laboratory, Yale XJntversity 



INTRODUCTION 



The following notes deal with certain of the very remarkable 

 fossils discovered by the late C. D. Walcott in the Middle Cambrian 

 Burgess Shale. The material examined was all collected by Wal- 

 cott at the now celebrated locality " on the west slope of the ridge 

 between Mount Field and AVapta Peak, 1 mile [1.6 km.] northeast 

 of Burgess Pass, above Field, British Columbia." The present con- 

 tribution is submitted in the belief that the forms discussed are of 

 considerable interest to students of living invertebrate animals 

 though they are likely to be somewhat neglected by palaeontologists 

 on account of their isolated occurrence as fossils. The diverse 

 systematic positions of the two forms discussed makes it desirable 

 to present the material in two parts; it is, however, convenient to 

 assemble all the photographs on a single plate at the end of the 

 second contribution. 



My very best thanks are due to the authorities of the United States 

 National Museum, and in particular to Dr. Charles E. Resser, who 

 most generously provided every facility for the study and descrip- 

 tion of the material in their charge. To Doctor Resser I am particu- 

 larly grateful for the photographs which constitute Plate 1. 



I am also much indebted to Prof. Alexander Petrunkevitch, of 

 Yale University, who has freely given me access to his immense store 

 of knowledge and to his beautiful preparations of Arthropoda; to 

 Dr. L. A. Borradaile, of Selwyn College, Cambridge, England, who 

 some years ago allowed me to transcribe certain parts of his valuable 

 notebooks relating to the Arthropoda, which have been of great value 

 in the present work; and to Miss L. Krause, artist to the Osborn 

 Zoological Laboratory, for the trouble she has taken over the re- 

 construction of the animals under discussion. 



I. ON OPABINIA AND RELATED PALAEOZOIC ANOSTRACA 



Branchiopod Crustacea of the Burgess Shale. — Walcott (1912) 

 described eight new genera of Branchiopoda in his collections from 

 the Burgess Shale. Four of these genera were placed in a new 



No. 2854.~Proceedings U. S. National Museum. Vol. 78, Art. II 

 2661—30—1 1 



f^cr'T OX) 



