5. LAGBNOEHTNCHUS. 271 



■whidi were in the inteiinaxillary, and in the lower jaw there were 

 four or five hidden (see Poehnan, Bull. Acad. Eoy. Belg. xvii. 608, t.). 

 Length 237 miUim. Black, lower part of the beak and the body 

 to the reproductive organs shining white; a white band forms a 

 line under the dorsal to the base of the tail ; above yellow, beneath 

 white. 



5. Lagenorhynchns clanculus. 



Skull wide and rather high behind. Beak flat ; outhne wide at 

 the base, rapidly tapering and acute in front, but rather convex on 

 ■the sides, these being slightly rounded ; the hinder edge near the notch 

 only slightly turned up and rounded. Triangle to near the middle 

 of the beak. Lower jaw high behind. Teeth ^, small, cylindrical, 

 curved, rather -acute at the tip ; the lower front one very small. In- 

 termaxillaries broad, hard. 



Lagenorhynchus clanculus, Gray, Proc. Zoal. Soc. 1849, 2 ; Ann. Sf 

 Mag. N. H. 1849, v. 48 ; Zool. Erebus ^ Terror, t. 35, ined. (skull) ; 

 Cat. Cetac. B. M. 1850, 102, 



a. SkuU. Pacific Ocean. From Dr. Dickie's Collection. 



Length, entire 14| inches. 



Length of beak ; 7^ „ 



Length of skull 7$ „ 



Length of teeth-line 6-|- „ 



Length of lower jaw lis „ 



Length of symphysis, lower jaw l| „ 



Width at notch 4^ „ 



Width at orbit • 7\ „ 



Width at middle of beak 2\ „ 



Width of intermaxillary in middle .... li ,, 



Width of condyles above 2| „ 



Very peculiar for the elongation and reflexion of the beak before 

 the notch, and the regular bevelUng of the sides of the beak. 



6. Lagenorhynchus breviceps. 

 Blackish ; under part white ; pectoral fin dusky. 



DelpMnus breviceps, Pucheran, Voy. Dumont d' TJrviUe, t. 22. f. 1. 

 Beak very short ; snout produced. Beak of skull depressed, only 

 slightly longer than the length of the brain-cavity. Teeth ■^^. 

 Inhab. Eio de la Plata. 



7. Lagenorhynchus Thicolea. 



Skull rather narrow behind. Beak elongate, about one-fifth longer 

 than the length of the head, rather dilated and concave above be- 

 hind, with the side edges in front of the notch elongate, keeled, and 

 turned up ; the middle of the beak flat, with flat shelving sides, the 

 shelving part beiag broader and forming a slight keel in front. In- 

 termaxiUaries flat, gradually tapering. Triangle to near middle of 



