ir. THE TROPIDOl.KrrUS FAUNA AT CANANDAIGUA 



LAKE, NEW YORK, WITH THE ON'I'OGENY 



OF TWENTY SPECIES. 



Bv Percy E. Raymond. 



General Introduction. 



The present paper is composed of two distinct parts, the first part 

 being of a biological nature, and representing the results of work done 

 at the Yale University Museum under the late Professor Beecher ; and 

 the second a faunal paper, prepared under the direction of Professor 

 Williams, also at Yale. 



An abstract of the first part of the paper giving the more general 

 results in condensed form, was published in the American Journal of 

 Science, Vol. XVII, April, 1904. The details are now presented, 

 illustrated by about forty figures and one plate in addition to those 

 which accompanied the abstract, and several species are here discussed, 

 ^vhich were not touched upon in the previous paper. 



I wish to acknowledge my indebtedness to that great pal'eon- 

 tologist. Dr. C. PI Beecher, not only for his guidance in the prepara- 

 tion of this paper, but for his help and continual inspiration for work 

 in the field of research. The figures are the work of Mr. Sidney 

 Prentice, draughtsman in the Section of Paleontology at the Carnegie 

 Museum. Most of them are from camera lucida sketches. The plates 

 are from photographs taken by Professor Beecher and the writer. 



A set of the specimens on which the first part of the paper is based 

 has been deposited by the writer in the Carnegie Museum, and figures 

 1-3. 5-12, 14, 15' 24, 26-29, T^i, 34, 42-45' 47-48 are drawn from 

 individuals in this collection. The series represented in the plates are 

 the property of the Yale University Museum. 



PART I. 0\ THE DEVELOPMENTAL CHANGES OF SOME OF THE 

 COMMON DEVONIAN BRACHIOPODS. 



Introduction. 



Certain layers of impure, clayey limestone from the Moscow (Ham- 

 ilton) shales in a ravine near Canandaigua Lake, N. Y. , were found 

 6 79 



