vill LIST OF PLATES. 
PLATE ae ad 
XLIII. THE HALTER AND TYMPANIC ORGAN - - - 610 
XLIV. THe AUDITORY MECHANISM - = = - 624 
XLV. THE DORSAL VESSEL - - - - - 640 
XLVI. THE PERICARDIAL SEPTUM - - - - 646 
XLVII. THE FEMALE GENERATIVE ORGANS - > - 666 
XLVIII. SPERMATOGENESIS - - - = = - 694 
XLIX. DEVELOPMENT OF THE OVARY - - - - 698 
L. THE INVAGINATED SEGMENTS OF THE MALE - - 736 
LI. THE MALE ORGAN- - - - - - 738 
Da sy “f ” : - - - - - 740 
