XXVI CONTENTS. 



No. of 

 Preparations. 



Subclass IV. Heterologous union 47 48 



Subseries VI. IN MAMMALS. 

 Subclass I. Dichotomy. 



A. Anterior Dichotomy. 



* In Animals. 



a. Diprosopus 49 61 



b. Dicephalus 62 64 



B. Posterior Dichotomy. 



* In Animals. 



a. Dipygus 6567 



b. Schizorhachis 68 80 



c. Schizocotis 81 84 



d. Schizocephalus 85 86 



** In the Human foetus. 



a. Schizorhachis 87 



b. Schizocotis 88 89 



C. Antero-posterior Dichotomy 90 94 



Subclass II. Homologous union. 



A. Prozygosis 9598 



B. Opisthozygosis 99 104 



C. Parazygosis. 



a. Xiphopagus 105 



b. Thoracopagus 106 117 



c. Pleuropagus 118 121 



d. Pygopagus 122 



Subclass III. Homologous union with dichotomy. 



Subclass IV. Heterologous union. 



A. By Impaction. 



a. Between the halves of the sternum . . 123 130 



b. Between the facial arches 131 133 



B. By Inclusion 134 137 



C. By Adhesion. 



a. Craniopagus 138 



b. Ischiopagus 139 



CLASS III. EXCESS OP GROWTH. 



[Arranged in the Osteological Series. ,] 

 CLASS IV. ARREST OP GROWTH. 



[Arranged in the Osteological Series.] 

 CLASS V. ARREST OP DEVELOPMENT. 

 Subclass I. Cranial arrest. 



IN PISHES 140 142 



IN BIRDS 143144 



IN MAMMALS. 

 A. Facial arrest . , 145159 



