Jordan and Evermann. Fishes of North America. 2753 



over branchial arches; 16 to 20 large spinules along median line of back 

 and tail. Color plain brown; caudal fin darker, edged with white. 

 This species differs from Vrolophua asterias in having a wider disk, more 

 acute snout, much smaller prickles, and fewer spinules on back and tail. 

 Mazatlan. Three specimens obtained in the Astillero, the longest 18 inches 

 in entire length. (This species is named for Dr. George Warren Rogers, a 

 scholarly physician, native of Vermont, but long resident in Mazatlan.) 



Urolophus rogersi, JORDAN &. STARKS, Fishes of Sinaloa, 388, 1895, Mazatlan, Mexico. 

 (Type, No. 1700, L. S. Jr. Univ. Mus. Coll. Hopkins Exped. to Sinaloa.) 



Page 88. In the key at top of page for RMnopterince read Myliobatince. 



132. AETOBATUS LATICEPS (Gill). 



This species is probably not different from A. narinari and may be 

 omitted. We find no differences between specimens from Mazatlan and 

 the West Indies. The following description isbased upon Mazatlan speci- 

 mens : 



Length of disc If in width; proximal of anterior margin of pec- 

 toral fins straight, distal convex; posterior margin concave, the end 

 of each ray forming a small scallop ; lateral angle sharp. Snout forming 

 an angle, from its tip to division of nasal lobes, 1^ times breadth of head ; 

 width of snout li times distance from its tip to the division of nasal lobes ; 

 nasal lobes projecting back over the mouth; width of mouth 1 its dis- 

 tance to tip of snout; numerous blunt buccal- papilke around upper den- 

 tal plate and on ridge between nostrils; interorbital 4f in disk; eyes 

 smaller than spiracles, which are as long as base of dorsal. Ventrals well 

 rounded, 3| in length of disk; tail 3| times disk. First caudal spine 

 equals base of dorsal, which is ^ second spine. Color bluish black 

 with many round yellowish spots scattered equally over the back and 

 ventral fins ; spots about as large as eye on back, smaller on head, some- 

 times two spots run together forming an elliptical spot, about 16 spots 

 from eye along anterior margin of pectoral to lateral angle; posterior 

 margin of pectoral very narrowly margined with white; ventral side 

 pearly white. JFrom the description of Aetobatus laticeps this species 

 differs in the following respects: Disk not so broad; tail not so long; 

 width of head and snout less; ventrals not truncated behind; pectorals 

 not margined with blackish; spots on ventrals not assuming the form of 

 ocelli. (Jordan.) 



Page 87. For the description of Pteroplatea crebripunctata in text sub- 

 stitute the following: 



Width of disk twice length to posterior end of anal slit; snout forming 

 a regular curve from a little in front of middle of pectorals, a very small 

 blunt projection at tip; anterior margin of disk convex near snout and 

 lateral angles, pectorals concave medially; posterior margin weakly con- 

 vex; posterior angle broadly rounded; lateral angle sharply rounded; 

 distance from snout to a line drawn through lateral angles, 2 times in 

 distance to tip of tail. Interorbital a little wider than its distance to tip 

 of snout; eyes twice spiracles; mouth equals snout, 6 in disk. Tail rat- 



