PLATE 63. 



Pelvis of PLATOSOMIA. 



Fig 

 Fig 

 Fig 

 Fig 

 Fig 

 Fig 



Upper and lower surface. 



Uraptera agassizii. M. C. Z. 549 (Page 367). 

 Narc^-Cion californicus. M. C. Z. 43 (Page 311). 

 Urobatis .sloani. M. C. Z. 3.5 (Page 402). 

 Taenidra lymma. M. C. Z. 23 (Page 399). 

 Da.sybatus marinds. M. C. Z. 641 (Page 382). 

 Pteroplatea altavela. M. C. Z. 386 (Page 415). 



The pelvis of the Raiidae, fig. 1, with tlie lateral prepelvic processes, recalls that of Cyclobatis, 

 a fossil genus. The pelvis of Narcacion, fig. 2, is raioid, but is more arched backward in the middle. 

 Figures 3-6 represent the Dasybatidae, in which family the organ is more like that of the Antacea, which 

 have neither lateral nor median processes in front of the pelvis. 



