1. PONXOPORIA. 231 



tt Teeth early deciduous, conical. Dorsal none. 



12. Beluga Teeth in both jaws, early deciduous. Male without any 



norn-liko tooth. -^ 



13. MoNODON. Teeth very early deciduous. Male with a proiectino- 



spiral tusk in the upper jaw. ° 



A. mad more or less beaked: beak of the skull slender, as long as or lonqer 

 than the brain-cavity. The lateral xvinys of the maxilla cvpanded, 

 honzonta. Trmmjle m front of the blowers fiat or concave. Delphi- 

 nuia. iJottle-uoses. 



* ^"^l^ f '^"•' *^"^ f'^'^'-''" ^^'"'^ ^^'^ brain-case, compressed. Si/mph/sis of 

 the lower jaw elongate. Dorsal fin distinct. J x J J 



1. PONXOPORIA. 



Head with a very long, slender beak. Elowhole transverse, on the 

 crown. Dorsal fin hig h, _falcatG, central ; pectoral fins rather elon- /^ 

 gate, sublimate. SkuTTl^SiniSish ; beak very long, compressed, with ^^^O/^^ 

 a strong groove on each side above ; side of the maxiUa rather ele- "^ 



vated; the edges form a ridge on the side of the upper surface of 

 the bram-cavity; eyebrow with a long cylindi-ical crest; lower iaw 

 compressed with a deep groove on each side ; symphysis very long. 

 Teeth small, subcylmdrieal, smooth, rather hooked, acute. 



^*ractoS' ^^'■'''''*'' -^'^'■*- '^"y- ^"'^'- ^^'''<^- 31- t. 23 (not cha- l8UJ 



1. PontoporiaBlainvillii. The Pontoporia. 



SkuU, with the tubercles behind the blowholes, broad sKo-htlv 

 convex; eyebrows with a strong, longitudinal crest; uiper%nd 

 lower jaw with a deep, weU-defined ridge on each side. Teeth ^l 

 small, conical, hooked, smooth ; symphysis more than half the length 

 01 the lower jaw. ° 



Delphinus Blainvillii, Freminville, Mm. Paris 



3S!x£,'isr '"''''^' ^'^' '''■' ""'"■ ^'^^- ^*-- 18^' 



D. (Stenodelphis) BlainviUei, Gervais ^- D'Orb. Voy. Amer Merid 

 Mamm. 31. t. 23 (skull) ; Reichb. Cetac. 128. 70. t 24 T78 



cftac'p Af'm^'' '^''"^' ^''"^' ^' ^' ^" ^- *• ^'^ ^'^'"^^'' <^«'- 

 Inhab. Monte Video. Skull, Miis. Paris {M. Freniinville). 

 M. Fromin^^Uo described the Dolphin belonging to the skull as 

 white, with a black dorsal band, and 4 foot long. 



Length of skull 22 g' 



Length of beak g y 



Length of S}-mphysis 5 9 



Length of teeth-line ' 5 4 



M. d'Orbigny believes the dolphin he observed near the mouth of 



