498 Memoir Sears Foundation for Marine Research 



Distinctive Characters. This Devil Ray closely resembles Mobula hypostoma in general 

 appearance as well as in the position of the mouth; but it is set apart from Mobula and 

 from all other Devil Rays by having no teeth on its lower jaw. 



Figure 115. Ceratobatis robertsii, female, 770 mm wide, from Jamaica (British Museum [Natural History]). 

 J Lower surface of head. B Right-hand nostril with nasal curtain rolled back, and outer part of tooth band. 

 C Side view of dorsal fin. D Ventral view of pelvic fins. E Teeth. Drawings by Hubert Williams. 



Description.^^"^ Proportional dimensions in per cent of extreme breadth of disc. 

 Female, 770 mm broad, from Jamaica (Brit. Mus. [Nat. Hist.], type, 1897. 7. i. 40). 

 Disc: length 51.5. 

 Snouth length: in front of mouth 3.6. 



122. Based on measurements and notes by Miss Ethelwyn Trewavas, British Museum [Natural History], and on draw 

 ings by Hubert Williams, of the type specimen. 



