THE SIGNIFICANCE OF SCUTE AND PLATE 

 "ABNORMALITIES" 1 IN CHELONIA. 



A CONTRIBUTION TO THE EVOLUTIONARY HISTORY OF THE 

 CHELONIAN CARAPACE AND PLASTRON. 



H. H. NEWMAN. 

 CONTENTS. 



PART I. 



PAGE. 

 I. Introduction. 



1. Statement of the Problem 68 



2. Nomenclature. The Normal Plate and Scute Pattern: (a) Plates; 



(/;) Scutes 6 9 



II. Discussion of the Present Status of the Question Concerning the Morph- 

 ology of the Chelonian Armor. 



1. Paleontological Data 7 1 



2. Embryological Data 7 2 



3. Data Derived from Comparative Anatomy 74 



III. Description and Discussion of Abnormalities. 



1. Inframarginals 77 



2 . In terpl astrals 80 



3. Supernumerary Scutes in a Row on the Carapace 81 



4. Supernumerary Scutes in a Row on the Plastron 93 



5. Correlated Abnormalities in Scutes and Bony Plates, with Discussion 



Regarding the Relationship Between these Two Structures 94 



6. Correlation in Scute Abnormalities 9& 



I. INTRODUCTION. 



I . Statement of the Problem. 



During a residence of several years on Lake Maxinkuckee, 

 Marshall County, Indiana, my attention was repeatedly attracted 

 to the large numbers and variety of species of tortoises that 

 are found in the lake and in its accessory streams, swamps 

 and pools. 



In the spring of 1903 I began a study of the habits, variations, 



'The word "abnormalities" in the title is used for lack of a better one, and 

 includes supernumerary scutes and plates, deficiencies in these structures and cases 

 of fusion. The word " diversities " might have been used with equal appropriateness. 



68 



