Doering: Lepyronia quadrangularis. 



583 



PLATE LX. 



fh stcrrtife 



mr fh p'e "r ife. \^- - 



Lateral 

 valve 



afh sfernite 

 HE pleurite 



' IL pkunte 



aih feraife rv 



lateral valve 



Ventral valve 



Dorsal valvi.. 



