240 DELPHINIDiE. 



• Beak of skull twice as long as the brain-eavity. Teeth H-f f . No. 2. 



** Beak moderate, once and a half the length of the brain-cavity. Teeth 

 If or If. No. 3. 



c. Skulljlattened behind. Triangle to the teeth-line. Palate flat, not grooved 

 on the side. No. 4 



a. SkiiU rornid. Triangle not reaching to the teeth-line. Palate convex, tcith 

 a very concave line on the hinder part of each side. Beak twice as long 

 as head. Teeth fg-. 



1. Delphinus microps. The Small-headed Dolphin. 



Skull small, subglobular. Palate convex. Nose very long, slender, 

 twice as long as the length of the brain-eavity, nearly four times as 

 long as broad at the notch ; intermaxiUaries convex above, with a 

 broad cavity between them in front, rather contracted in front of the 

 blowers. Teeth ^. MaxUlaiies very spongy. The triangle in front 

 of the blowers short, not nearly reaching to the line of the hinder 

 tooth. Palate with a prominent ridge extending along its hinder 

 two-thirds. 



Delphinus microps, Gray, Zool. JErehus 8^ Ten-or, 42. t. 25 (skull) ; 

 Cat. Cetac. B. M. 1850, 126. 



Inhab. Coast of Brazils (Dr. DicMe). Near mouth of Eio de la 

 Plata, Mus. Buenos Ayres (Burmeister). 



a. SkuU ? From the Haslar Hospital. The specimen figured 



in the ' Voyage of the Erebus and Terror,' tab. 25. p. 42. 



b. Skull, larger; the skull behind the frontal longer, slightly com- 



pressed. Teeth |^ on each side. Length, entire, 18 inches ; 

 tooth-line 10|, beak 12, lower jaw 15| ; width at orbit 6|, at 

 notch 3, middle of beak 1|. 



This skull chiefly differs from the type skuU of D. microps in the 

 back of the skull being much less convex, and in its being of a rather 

 larger size ; can this depend on the sex of the specimen ? 



Dimensions of five skulls, in inches: the 1st is in the Norwich 

 Museum ; the 2nd, in the British Museum ; the 3rd, in the MuSeum 

 of the Eoyal College of Surgeons ; the 4th, in Dr. Dickie's collection ; 

 the 5th, in the Edinburgh College, n. 164. 



1. 2. 3. 4. 5. 



in. in. in. in. in. 



length, entire 17^ 15| 15 18 16^ 



Length of nose 9| 11 10| 



Length of teeth-line 8 8| 



Length of lower jaw 14| 13 12| 



Width at notch 2^ 2^ 4 3 



Width at orbits 5| 6 



Width of middle of beak 2| 2^ 1| 2| 



Width of intermaxiUaries .... 8 9 . . 2 



Var. 1. SkuU in Mus. Coll. Surg. Edin. n. 164. Barclay Collec- 

 tion. Head smaller, and the nose rather shorter, only once and three- 



