384 CALIFORNIA ACADEMY OF SCIENCES. 12 



than half distance from tip of snout to mouth. Dorsals 

 sub-equal ; first dorsal inserted in advance of ventrals ; 

 about half its base over ventrals; caudal, with a lower 

 lobe, which is equal to slant height of pectoral; tail with 

 a keel on side. 



Color, plain olive grey above, light below. 



Measurements — Length, 50 inches; caudal, 7 inches; 

 pectoral, 7 inches; dorsal front, 5^ inches; snout with- 

 out nostril, 11 inches. 



Type — A skin in L. S. Jr. Univ. Museum. 



Common in brackish waters at the mouth of the Rio 

 Presidio, where one fine specimen was obtained. The 

 species is also recorded (as Prist is perroteti) by Dr. 

 Gilbert from Mazatlan, and by Dr. Gunther from Chiapam. 

 Dr. Gunther identifies this species with Pristis perroteti 

 described by Miiller & Henle, from the Senegal River. 

 In view of the great difference in the fauna of the Gulf 

 of California from that of Equatorial Africa, this identi- 

 fication may be questioned, especially as there are several 

 details in which the description of Pristis perotteti differs 

 from our fish. 



We append the description of Miiller & Henle, as also 

 the descriptions given by Latham of his Pristis antiquorum 

 and Pristis pectinatus, together with our account of the 

 common saw fish of the Gulf of Mexico, usually and 

 probably correctly identified as Pristis -pectin at l us Latham. 



The following is the original description of 



"Spec. 4. Pristis Perotteti, N. 

 Kopf. " Die Form des Kopfes und der Naslocher wie Pristis antiquorum. 

 Die Sage lauft nach voru sehr allrnahlig spitz zu. Sie ist an der 

 Basis 1 Zoll 7 Linien, an der Spitze zwischen den beiden letzten 

 Zahnen 10 Linien breit, 19 Zahne jederseits. Diehintersten Zahne 

 sind kurz, wahrscheinlich abgenutzt. Die vordersten sind etwas 

 breiter als die Halfte der Breite der Sage, alle am hintern Eande 

 gerinnt. Die hintern Zahne stehen weit aus einander, um 5-6 Mai 

 die Breite des Zahns. Die vordersten sind einander etwas mehr 



