PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 37 



Moutli broad, its widtli equal to the distance from its front margin 

 to tlie tip of the snout ; a deep crease passing around the mouth 

 behind, in front of which the lower lip has three folds of skin. Upper 

 lip not developed, a strong- fold of skin passing from the angle of the 

 mouth on either side to the inner angle of the nostrils, thence straight 

 across, joining its fellow on the opposite side, these folds enclos- 

 ing a depressed, subtriangular, / \ -shaped area, which is bounded 



behind by the curved outline of the upper jaw. In this depression are 

 three transverse cross-folds of skin. jS'ostrils broader than the interval 

 between them, with a free fold behind, which is prolonged forwards and 

 inwards in the middle, the rest of the fold being turned backward. An- 

 terior edge of nostrils with a broad tlap, the outer edge of which is much 

 prolonged, overlapping the i)osterior flap, the inner edge covering the 

 inner angle of the nostril. 



Both jaws strongly and somewhat regularly curved. Teeth numerous, 

 rather sliarp, about fj, about twelve in a cross-series. Gill openings very 

 narrow. 



Skin everywhere covered with a rather fine shagreen, almost precisely 

 as in Uliinohatus productus. The asperities are smaller below, and 

 coarser on the outer anterior margin of the pectorals, where tbere are 

 also two or three irregular rows of sharp, curved, backward-directed 

 spines. Four strong spines on the tip of the snout, forming a rhombic 

 figure ; four or five strong, bluntish spines around each eye, above and 

 in front, the one at the upper anterior angle the largest. 



A series of 22 very strong spines along the median line of the back 

 and tail, and two more on the tail between the dorsal fins. On each 

 side of the tail above is a similar series of ten spines, the first opposite 

 the end of the base of the ventrals, the last opposite the front of the 

 first dorsal; a single strong spine on the outer edge of the shoulder-gir- 

 dle and two between the spine and the dorsal series. 



Color almost exactly as in Rhinobatus productus. Olive-brown above, 

 whitish beneath, the vertical fins paler. Eostral area and edges of pec- 

 torals somewhat translucent. No sharp markings of any kind anywhere. 



Measurements. 



Extreme lengtli 17.90 inches. 



Length of disk 7, 25 inches = 1.00 



Width of disk 1.09 



Width of tail at base "^0 



Distance between outer humeral spines 30 



Length of branchial area .ir> 



Width of branchial area in front - .34 



Width of branchial area behind 28 



Distance between outer edges of nostrils 21 



Width of mouth 20 



Width of interorbital area • 1^5 



Length of eye 00 



Length of snout from eye • 225 



