ADDENDA TO MARSIPOBRANCHII, ELASMOBRANCHII, ETC. 69 



tnre of ja\A\s, the sinallor size, and the two ciitaueous expansions. Of 

 twenty specimens the average proportional length of body and tail is as 

 four and a half to eight. Tu no case is the tail twice as long as the disk. 

 Color ochraceous brown ; ventral surface light. Length of body of an 

 adnlt male 9.4, length of tail 15, and width of pectorals 10 inches. Com- 

 mon in the rivers of Florida along tlie Gulf coast. Several specimens 

 in the collection were captured in Lake Monroe, at a distance from the 

 salt water, by Count Pourtales. 



Dasibatis sayi. 



Jiaja saifi Lesneur, Jour. Acad. Nat. Sci. Phil, i, p. 42, fig. 

 ^1 i)lwhat'i!i m>i\ DeKay, New York Fauna, Fish. p. 376. 

 Tnjijon Huiji Jllill. et Heule, Plagiostomen, p. 16G. 

 Mylloballs sayi, Storer, Syu. Fish. N. Ainer, p. -20)2. 

 2'rijijon sayi, Dumeril, Elasmobrauch. p. (503. 



Disk quadrangular, about one-sixth wider than long, anterior margins 

 nearly straight, jiosterior and inner borders convex, outer and posterior 

 angles rounded. Snout not protruding beyond the lines of the margins. 

 Ventrals rounded. Tail strong, rather more than one and a half times 

 the length of the disk, with a strong serrated si)ine, bearing a short, 

 low cutaneous expansion behind the spine on the upper side, and a 

 longer, little wider one below, ending nearly opijosite. Upper jaw undu- 

 lated ; lower prominent in the middle. Teeth small, smooth in young 

 and females, sharp in adult males. Three papiilie at the bottom of the 

 mouth, and one at each side. Body and tail naked. Color olive brown 

 in adult, reddish or yellowish in young ; lower surface whitish. This 

 species closely resembles the European species pastinaca. A compari- 

 son of specimens discovers the following differences: in Sayi tlie ante- 

 rior margins form a more bkmt angle at the end of the snout, which is 

 less prominent at the apex, the outer and posterior extremities of the 

 l)ectorals are rounder, the posterior margins are more convex, the disk 

 is broader toward the ventrals, and the tail is longer; in paHtinaca 

 the lateral and hinder angles of the pectorals and the lateral angle of 

 the ventrals are marked by blunted corners. A single small rounded 

 tubercle on tlie middle of the back. There are specimens in the col- 

 lection from New York, Pensacola, Bahia, and Rio Janeiro. A young 

 female measured from snout to tail 7.1, length of tail 11, and width of 

 pectorals 8.2 inches. 



