156 BELPUIXIDiE. 



is developed. (Monophyodont). The stomach has several distinct pouches, 

 usually five. They have several distinct spleens. Many of them have a 

 dorsal fin, which however is only a simple prolongation of skin devoid of 

 any independent movement, and not connected in any way with the vertebne. 



The spiracle, or blowhole, is single or double. This does not serve as 

 an organ of smell, but is used as a respiratory aperture. It has generally 

 been beheved that the water taken into the mouth along with their prey 

 is expelled through this aperture in a jet, forming the so called spouting 

 of whales ; but of late it is confidently asserted that water is never ex- 

 pelled this way, and that it is simply the moisture of the lungs and 

 air passages expelled along with the expired air which causes the jet or 

 spouting. 



The Cetacea are divided into the famiUes, Delphinidce or Porpoises, and 

 BalcBnidm, or Whales, both of which have representatives in the Indian 

 Seas. 



Fam. DELPHINID.E. 



Teeth numerous, conical ; nostrils open by a single transverse aperture ; 

 head of moderate size ; candal fin notched. 



The cranium is broad and high ; the nasal passages nearly vertical. The 

 maxillaries are prolonged anteriorly, and also much developed posteriorly, 

 rising anterior to the frontals, over which they are expanded, extending as 

 far as the level of the nasals, which form the summit of the cranium. 

 They have in general no coecum. 



The dolphins, or porpoises, as they are popularly called (the word dol- 

 phin being usually restricted to the fish, Coryphaena, celebrated for its 

 changeable tints when dying), are found all over the world, inhabiting 

 seas, and many ascending large rivers. They generally associate in flocks 

 or shoals, are very active, swimming and playing near the surface of the 

 sea, and feeding on fishes, Crustacea, cuttle-fish, &q. They often accom- 

 pany ships for miles. There are several genera recognised, one of which 

 is peculiar to the rivers of India.* 



Gen. Delphinus, Linn. 



Chav. — Rostrum narrow, of moderate length, continued abruptly from 



• Materiala for the elucidation of tMs family as represented in India are very deficient, and I 

 am only able to indicate the names of some. Professor Owen has recently read a paper on those 

 collected by Walter Elliot, on the east coast, desci'ibing several new species, but the paper is not yet 

 published. I will introduce, in an Appendix to this volume, the species there described, if published 

 before the work is completed. 



