560 DR. J. E. GRAY ON THE BOTTLENOSED WHALES. [NoV. 12, 



tympanum very large, but not very distinct ; eustachian tubes 

 moderate. 



Pachybatrachus robustus. 



Head large and broad, snout slightly longer than the eye, and the 

 loreal region nearly vertical. Eye large, tympanum very large. 

 Digits with their extremities rounded and with subarticular tuber- 

 cles. Skin entirely smooth. A glandular fold extending from the 

 eye to the anus, and sending down a branch behind the tympanum. 

 Upper parts dark brown ; glandular fold, tarsus, tibia, arm, and 

 middle of back with black markings. Under parts lighter, and free 

 from black markings. Transverse light markings on the hindei 

 part of each upper eyelid. 



The typical specimen has been deposited in the national collection. 



3. Note on the Bottlenosed Whales {Tursio). 

 By Dr. J. E. Gray, F.R.S., V.P.Z.S., &c. 



A short time ago the British Museum received three skeletons and 

 a skull of the Bottlenosed Dolphin {Tursio truncatus), which were 

 obtained from one school by Edward Gerrard, jun., in the Firth of 

 Forth. They show the very great change that takes place in the 

 form of the skull, and especially of the beak, during the growth of 

 the animal. 



The beak of the skull of the young animal is regular, conical, 

 tapering and contracted in front. The skull is l/j inches long, 

 with the beak, from the notch, 85 inches, and the teeth-line, by the 

 callipers, 8 inches. The teeth are small, conical, acute, three and 

 one-half in an inch. 



The skull of a full-grown female is similar but larger than that 

 of the young animal. 



There is another skull of a full-grown animal of the same school, 

 but its sex was not determined. It is very like that of the female, 

 but rather larger. 



The skull of the very old male animal (fig, 1, p, 561) is much 

 thickened ; but the great peculiarity is that the beak is broad and 

 flattened, and very much expanded, flattened, and curved up at the 

 tip in front, and as if part of the beak in front had been absorbed. 

 The teeth have nearly all fallen out, and there is only one left, which 

 is spread out towards the edges and flattened, and evidently would 

 have fallen out in a very short time. The intermaxillary and palatine 

 bcnes are visible nearly to the back part of the palate of the beak. 

 The length of the skull is 20| inches, of the beak, from the notch, 11 1, 

 of the teeth-line 9|. Width of the brain-case at eyebrows 11^, of 

 beak at notch 6, in middle (or tenth tooth) 4^^. 



There is a considerable difference in the form of the pterygoid 

 bones and of the sheath of the hinder nasal opening in these four 



