10 PEOPESSOK PLOWEE ON EISSO'S DOLPHIN. 



skull of the animal next to be described are also appended for convenience of com- 

 parison) : — 



Skull of adiilt. Skull of young. 



inches. inches. 



Entire length 19-2 13-6 



Length of rostrum' 9"3 6"1 



Breadth of occipital foramen 1'5 1'2 



Greatest height of occipital foramen 1"9 1'7 



Breadth of occipital condyles 4'5 3'2 



Greatest breadth of cranium (at parietal region, in temporal 



fossa) 9-1 7-7 



Greatest breadth of skull (at zygomatic process of 



squamosals) 12"9 9"0 



Breadth at anteorbital processes of frontals 11 "8 8'2 



Breadth of anterior narial apertures 2-8 2'2 



Breadth of rostrum at base (bottom of anteorbital notch) . 7*7 5'6 



Breadth of rostrum at the middle 4'4 3-3 



Length of tympanic bone 1"8 1'6 



Mandible. — Length of ramus 15'4 10'6 



Length of symphysis 1'9 1-2 



Breadth at condyles 11 



Height at coronoid process 4'3 2*7 



Hyoid. — Breadth between tips of thyro-hyals 8'7 



Basi-hyal. — Greatest antero-posterior length 3 



The bones of the pectoral limb generally present a nearer approach to those of Gloli- 

 cephalus than any other Cetacean, or, rather, may be described as intermediate between 

 that genus and BeJpMmis proper. 



Of the two scapula figured by Van Beneden and Gervais, one of G. rissoanus, and 

 the other of G. griseus, the present one most nearly resembles the latter in outline, 

 especially in the form of the acromion ; it is rather smaller, however, in all its dimen- 

 sions, in which respect it is more like the former. 



The humerus is immovably united with the radius and ulna. These bones are not 

 so broad in proportion to their length as in GloMcejjhalus. 



The carpal bones are five in number, and form a close mosaic, three in the first and 

 two in the second row, and have precisely the same arrangement as in Glohicephalus. 

 The pollex consists of a short, nearly square metacarpal, and a single, conical, tapering 

 phalanx, reaching nearly to the end of the second metacarpal. It is certain that no 

 other ossified phalanx was present in this digit on either hand — a circumstance which I 

 note particularly, because in Gervais's figures^ both of G. griseus and G. rissoantis, there 



' Measured from a line drawn between the anteorbital notches. ' Op. cit. pi. 54. figs. 10 & 5. 



