100 CETACEA. 



in. lin* 



Length to pectorals 20 



of pectoral 15 



to dorsal 41 



of dorsal 11 6 



Height of dorsal 10 



Width of tail 22 



Skull : Length, entire 18 



,, of nose 8 6 



Width at orbit 9 5 



at notches 5 6 



of middle of beak .... 3 6 



of lower jaw at condyles 8 



ttt Nose of skull longer than the length of the brain-cavity, 

 teeth-line some distance from the notch. 



3. LAGENORHYNCHUS ELECTRA. The ELECTRA. 



Skull rather depressed; nose flattened above, expanded and 

 reflexed on the side behind, rather shelving in front ; sides rather 

 contracted in the middle, rather longer than the head, and If the 

 length of the width at the notch ; intermaxillary broad, flattened, 

 nearly f of the width, with a large, wide groove for the greater 

 part of its length ; triangle flat, rather concave behind, with a 

 lozenge-shaped, rather raised, rugose space in the front half; 

 teeth f f , rather small, cylindrical, conical, slightly curved, acute, 

 four in an inch ; the lower jaw regularly converging, straight on 

 the sides in front, rather swollen behind, and shortly obliquely 

 truncated in front, the gonyx rather produced. 



Lagenorhynchus Electra, Gray, Zool. Erebus and Terror, 35. 



t. 13, skull. 

 Inhab. ? 



a. Skull ? Purchased. 



The specimen figured in the Voyage of the Erebus and Terror. 



Skull: length, entire, 17^ inches; of head, 8^; of nose, 9|; 

 of teeth line, / ; of lower jaw, 14 ; width of temple, 10^ inches ; 

 at notch, 5 j ; at middle of beak, 4 ; of intermaxillary, 2. 



This skull is very like the former, but it is considerably larger, 

 and the nose is longer in proportion, and the head is much more 

 depressed in the middle and spread out on the sides. 



4. LAGENORHYNCHUS C^ERULEO-ALBUS. 



Teeth ; white, back bluish, with oblique streaks on the sides* 

 belly white. 



