BY H, H. SCOTT. 171 



1913. 



This agrees very well with the osteology of the ziphioids, 

 ill which whales the ribs are slender and less Duuierous than 

 obtains in the dolphin group. Also, the sternal ribs are un- 

 ossified in the ziphioids, and as far as the evidence yielded 

 by the remains of the fossil animal goes, the sternals are 

 absent. Naturally this latter point must not be pushed too 

 far in dealing with fragmentary remains. 



The shapes of the rijjs in the fossil make many interesting 

 departures from the dolphin type, their sections conforming 

 to a more oval outline. 



The epiphyses of the centra approach more nearly to 

 Tnrsiops than they do to Delphinus. having the same amount 

 of flattening as they contribute moieties to the naural canal. 



From such fragments of ihe neural spines as have sur- 

 vived, I should judge them to have been more slender, and 

 taller than those found in the dolphins, which also agrees 

 with the osteology of an immature ziphioid, as far as it is 

 known, I have been unable to collect any trustworthy data 

 respecting the articulation of these fossil ribs, with their re- 

 spective diapophyses and centra. One specimen looked 

 promising, but as it has obviously sagged in the matrix I 

 reluctantly abandoned the quest. 



Coming now to the arm, which is tlie most perfect part of 

 the whole find. The ratios between the upper and lower arm 

 are agreeable with those found among ziphioids, as are also 

 the straighter shafts and more even development of the bones 

 of the lower arm. The departures from the dolphin group 

 may be thus recapitulated : — 



(1) Humerus more uniform in width throughout. 



(2) Ulna not constricted in the region of the olecranon 

 process. 



(o) Olecranon, a wide fan-like crest and not a mer^ 

 tubercle as in the dolphins. 



From the published descriptions of the Squalodotis it 

 differs in having the arm bones more flattened, and thus 

 making a nearer approach to the true whales ; as also in 

 having articular surfaces that ap^^arently manifest no ap- 

 proach to the land carnivora. 



Comparison with Eurhinodelphis is impossible since no 

 description of the arm bones is available to me — if indeed 

 these parts of the skeleton have been recovered. The exten- 

 sive cetacean collection of the British Museum is not enriched 

 with a single fragment of these creatures. In classification, 

 Dr. Beddard allies Eur Jiitiodel phis with the Platariistidcr, and 

 if this taxonomy is sound it would cut out the Table Cape 

 whale on the ratios of the upper and lower arm (vide supra). 



