I. GENUS SOTALIA S. SINENSIS AND PLUMBEA. 153 



SUBFAMII.Y I. DELPnixi:N^^. 



1. SOTALIA Gray. 



Kostrum long, narrow, and compressed. Symphysis of mandible 

 long or moderate. Pterygoid bones separate, narrow, and divergent 

 posteriorly. Postorbital process of frontal narrow. Teeth moderate, 

 smooth, 26 to 35. Vertebme 51 to 55. 



Head prolonged into a distinct beak. Dorsal fin falcate. Pectoral 

 fins broad at the base, talcate (oval in S. fluviatilis), moderate. 



Color white or gray, sometimes spotted; no bands of dark color. 



SOTALIA SINENSIS Flower. 

 (Plate 1, fig. 3.*) 



" Milky white, with pinkish fins and black eyes" (Swinhoe.) 



Teeth |. Vertebra?: C. 7; D. 12; L. 10; Ca. 22=51. 



Temporal fosste large, rounded. Rostrum rather broad at the base, 

 long, tapering. Palato-pterygoid region constricted. Inner margins of 

 pterygoids separated, parallel proximally, divergent distally. Crowns 

 of teeth smooth, conical, and incurved. 



Measurements of the skull. — Total length, 20.7 inches (52.6'='") ; length 

 of beak, 12.8 inches (32.5'^'") ; breadth of beak at base, 4.7 indies (11. 0-""); 

 breadth of same at its middle, 1.85 inches (4.7'^'") ; length of upper tooth- 

 row, 11.2 inches (28.4'='") ; greatest breadth at postorbital processes of 

 frontal, 8.8 inches (22.4«'"j. 



Hahitat. — Quemoy Island, harbor of Amoy, China. ? Foo-chow River 

 {Swinhoe). Canton 'River (Osbeclc). 



SOTALIA PLUMBEA (Cuvier). 

 (Plate 1, figs. 1 and 2.) 



Snout very long; distance from the tip of the snout to the eye one- 

 sixth the total length ; dorsal commencing at the end of the first third 



* The plates accompanying this synopsis contain, for the most part, reprodnctious 

 of the best figures of the different species to be found in the literature. For the fig- 

 ures of skulls I have drawn largely upon the admirable illustrations in the atlas of 

 Van Beneden and Gervais' Osteographie des Cetaces, and in Gray's Synopsis of Whales 

 and Dolphins. Most of the figures of species described by American authors, how- 

 ever, are new, and have been drawn from specimens in the National Museum. 



In the diagnoses I have attempted to give the mean number of teeth (on one side of 

 each jaw) for those species of which numerous skulls are to be found in the museums, 

 but in giving the number of vertebne I have in some cases indicated the extremes 

 of variation as far as known. 



