ON TWO DOLPHINS FROM MADRAS. 413 



Palatines W-shaped, with a long symphysis helow the pterygoids. 



Vertebra 49 to 55. 



Steno.— Teeth large, rough, and less numerous (20—27). Pterygoids 



in contact. 



Palatines not distinctly W-shaped, without a long symphysis below 

 the pterygoids. 



Vertebrae 65 to 66. 



This Trevandrum specimen, then, clearly belongs to Sotalia, as thu3 

 restricted. From the mention of the marked constriction in the body 

 immediately in advance of the caudal ridges (well shown in the figure), 

 it is further evident that the species is very nearly allied to the Indian 

 Sotalia lentiginosa ( 1 ), with which it agrees very closely, if not actually, 

 in the number of the teeth, these being given by Dr. Blanford as about 

 If iu th9 latter. Unfortunately, nothing is kuown with regard to the 

 number of the vertebrae in that species. 



Sotalia hnHyinosa is, however, popularly known as the speckled 

 dolphin, from the circumstance that the body and fins are profusely 

 spotted with elongated or pear-shaped flocks, some of which are white 

 and others lead-coloured. No traces of such spots are visible in the 

 Trevandrum specimen; and the question then arises, are they characteristic 

 only of the adult condition of S. lentiginosus ? To this question it is 

 impossible to give a definite answer ; but I am inclined to think that at 

 least some tracss of the spots would be observable in the Trevandrum 

 specimen if it were really the young of the spotted dolphin. Moreover, 

 the Trevandrum dolphin appears to differ from the species last-named 

 by the much more forward extension of the part of the back-fin, 

 which shelves off gradually into the line of the back, instead of rising 

 suddenly. I am therefore inclined to regard the two as distinct, more 

 especially as the colour in the sketch (although not in the description) 

 of the Trevandrum specimen is much lighter than in the description 

 of S. lentiginosa. With regard to S. plumbea, which has been 

 taken at Madras, the number of teeth (§|) is, I think, greater than 

 could have possibly occurred in the Trevandrum specimen (of which 

 the tip of the rostrum is slightly imperfect). Then, again, there is 

 no white on the under surface of that species, and no mention of 

 a sharp constriction in advance of the caudal ridges. With regard 



(') Steno lentiginosus of Blanford. 



