220 



BULLETIN 201, UNITED STATES NATIONAL MUSEUM 



way but was exactly like the same appendage in the female. He has, 

 accordingly, modified the original definition of the genus and relies 

 solely on the 3-jointed exopod of the fourth pleopod of the male to 

 separate the genus from Acanthomysis. 



PRONEOMYSIS WAILESI Tattersall 



Figures 93, 94 

 This species is diagnosed on page 249. 



Genus PARACANTHOMYSIS Ii 



Paracanthomysis Ii, 1936b, p. 7. 



This genus is closely related to the genera Acanthomysis and 

 Proneomysis and differs only in the structure of the exopod of the 



Figure 93. — Proneomysis wailesi Tattersall: a, Eye, X 45; b, endopod of third thoracic 



limb, X 75; c, telson, X 75. 



