CONTENTS PART I. INTRODUCTION --------------------------------------------------------------------------------------------1 Organization of the Atlas ------------------------------------------------------------------------------------1 Specimens and Collections ----------------------------------------------------------------------------------1 Plate Preparation ----------------------------------------------------------------------------------------------2 3-Dimensional Computer Reconstructions----------------------------------------------------------------2 Neurogenesis in Specimens (CR 15 to 18 mm) ----------------------------------------------------------2 References ----------------------------------------------------------------------------------------------------20 PART II. 15 mm Crown Rump Length, C9247 --------------------------------------------------------------------22 Plates 1-7 A/B ----------------------------------------------------------------------------------------------24-37 High Magnification Plates 8-21 A/B---------------------------------------------------------------------38-65 PART III. 15 mm Crown Rump Length, M2051 -------------------------------------------------------------------66 Plates 22-38 A/B -----------------------------------------------------------------------------------------67-101 High Magnification Plate 39 A/B --------------------------------------------------------------------102-103 PART IV. 15.8 mm Crown Rump Length, C492 ------------------------------------------------------------------104 Plates 40-56 A/B ----------------------------------------------------------------------------------------106-139 PART V. 18 mm Crown Rump Length, C1390 -------------------------------------------------------------------140 Plates 57-63 A/B ---------------------------------------------------------------------------------------142-155 High Magnification Plate 64 A/B -------------------------------------------------------------------156-157 PART VI. 17.

5 mm Crown Rump Length, M2155 ----------------------------------------------------------------158 Plates 65-81 A/B ---------------------------------------------------------------------------------------160-193 High Magnification Plates 82-84 A/B --------------------------------------------------------------194-199.