ON THE ANASPIDACEA, LIVING AND FOSSIL. Ag9 
On the Anaspidacea, Living and Fossil. 
By 
Geoffrey Smith, 
Fellow of New College, Oxford. 
With Plates 11 & 12 and 62 Text-figures. 
CoNnTENTS. 
PAGE 
1. HisroricaL INTRODUCTION : ; . 489 
2. EXTERNAL MoRPHOLOGY 3 : . 495 
(A) General Appearance : : . 495 
(B) Segmentation : ! . 500 
(c) Appendages : : : : . 002 
(D) Theoretical Considerations : . d2d 
3. INTERNAL ANATOMY. ; . 028 
(A) Pericardium, Heart, and aceular eee ; . 028 
(B) Alimentary Canal : : ; . 929 
(c) Excretory System : : : . O97 
(D) Reproductive Organs : : : 2 ood, 
(E) Muscular System . : : : . d42 
(F) Nervous System . : , : . O42 
(G) Theoretical Considerations 5 ; . 045 
4. BIONOMICS : : ; . 546 
(A) Habitat and Gitar al Habits , : . 946 
(B) Distribution 3 Z : . 348 
(Cc) Breeding and Reproduction : . o48 
do. THE RELATION OF THE SYNCARIDA TO OTHER MAatacos- 
TRACA 3 ‘ : ; : . 9090 
6. SysTEMATIC PART : : : . DOD 
1. HisroricaL InrRopUCTION. 
THE first members of the Anaspidacea to be discovered and 
described were certain fossil forms occurring in the Permian 
