2 1, a. Distributed coastallv in patches above Pt. Conception, rarely 

 ranging as far north as Barrow Alaska; 25-28 teeth in each upper 

 jaw, 22-26 teeth in each lower jaw. 



* Harbor Porpoise, Phocoam phocoinu (B) 



b. Distribution limited to upper end ot Gulf ot California in the 

 Colorado river delta and shallow margins of coast and oceanic 

 islands (rarelv reported); 20-2 1 teeth per upper jaw. 18 teeth per 

 lower jav\'. 



* Cochito. Phi 



ccci'na sinus 



22. a. Distinct dorsal hn absent, but may have small longitudinal dorsa 

 ridge near midpoint ot back Go to 25 



b. Distinct dorsal fin present, m middle or forward third ot back 

 Go to 24 



25. a. Body black with white hourglass pattern on bellv; dorsal tin 

 completely absent; beak very small but distinct: 57-49 extremely 

 fine peglike teeth per jaw; ma.ximum body length about 5 m; 

 distribution primarily temperate oceanic between about 50 N 



and 50 N. 



* Northern nght-whale dolphin, hssodclphis hortalis (A) 



b. Adults white, young slate gray or brownish; 8-1 1 teeth in each 

 upper |aw, 8-9 in each lower jaw; short broad rostrum; maximum 

 body length 4.5 m; distribution primarily arctic, above Unimak 

 Pass, though occurs in Cook Inlet, and rarely near Kodiak Island 

 and in Yakutut Bay. 



* Beluga or white whale. Dclphinaplcrus liucas (P) 



c. No visible teeth (or two teeth) in upper jaw of adults only; in 

 males (sometimes females) one or both teeth grow to a 2.7 m tusk 

 in left-hand (sinestrah spiral; no rostrum; ma.ximum body length 

 5 m; distribution arctic, rarely reported trom .Alaska. 



* Narwal, Monodon moncenos (P) 



24. a. Head blunt Go to 25 



b. Head long and conical; no demarcation of rostrum from melon; 

 cape very narrow except for slight widening beside dorsal fin; 

 20-27 teeth in each upper and lower jaw; crowns of teeth often 

 marked with many fine vertical wrinkles; maximum body length 

 2.4 m. 



* Rough-toothed dolphin, Sleno hrcJiinensis (B/T'i 



25. a. Teeth (2-7 pairs) usually at front end ot lower jaw only, teeth 



rarely in upper jaw); all teeth trom lower jaw of older specimens 

 may be absent or extensively worn; forehead with median crease; 

 dorsal fin tall, to 58.1 cm and distinct; maximum body length 

 4.0 m. 



* Risso's dolphin. Grampus ^nstus (A) 



b. Teeth (7 or more pairs) in both upper and lower jaws; forehead 

 with no median crease Go to 26 



59 



