58 CATODONTID.E. 



the outer wall of the postpalatine air-sinus. Symphysis of man- 

 dible of moderate or excessive length. No functional teeth in the 

 upper jaw. Mandibular teeth various, often much reduced in num- 

 ber. Lachrymal bones usually large and distinct. Bones of the 

 skull raised so as to form an elevated prominence or crest behind 

 the anterior nares. Orbit of small or moderate size. Pectoral limbs 

 small. Dorsal fin usually present." — Flower. 



Family 6. CATODONTIRE. 



Catodontina, Gray, I. c. pp. 386, 387. 

 Catodontidre, Gray, Syvops. Whales 8f Dolph. p. 3. 



Head compressed, truncated in front, very large. Blowers sepa- 

 rate, linear, in front of the upper part of the head. Mouth inferior, 

 linear. Pectoral fin short, broad, truncate. Dorsal hump rounded. 

 Skull elongate. Crown concave, surrounded by a high perpendicular 

 wall formed by the doubled-up maxilla and occipital bones. Upper 

 jaw toothless. Atlas free ; rest of cervical vertebra united by their 

 bodies and spines into a consolidated mass. 



1. CATODON. 



Catodon, Gray, I. c. pp. 190, 386, 387 ; Synops. Whales $ Dolph. 



p. 3. 

 Pkyseter, Flower, Trans. Zool. Soc. vol. vi. p. 309. 



The atlas vertebra transverse, nearly twice as broad as high ; the 

 central canal subtrigonal, narrow below. Skull nearly one-third the 

 entire length of the body. Lachrymal bone wanting. The zygo- 

 matic process is formed of the malar bone. Vertebral column rough 

 and rather spongy. Vertebra 50 : 7 cervical, 11 dorsal, 8 lumbar, 

 24 caudal. The atlas separate ; the other 6 cervical united by their 

 bodies and spines into one consolidated mass, and sometimes united 

 to the first dorsal vertebra. The atlas subquadrangular, broader 

 than long. The transverse process truncated. Upper edge nearly 

 straight, lower slightly curved. Neural canal triangular, one of the 

 angles directed downwards. The thyro-hyal triangular, thick in 

 front, thinner behind ; the basihyal broad and flat. The basi- 

 hyal and thyro-hyal united. The ribs long, all but the first slender 

 and light. The first rib is short, broad, and very thick near the 

 lower end. Sternum large, triangular, the apex turned backwards. 

 The broad front end nearly straight, composed of two large anterior 

 and a small posterior piece. Pectoral limb small. Scapula higher 

 than broad ; outer surface concave, inner convex. Acromion very 

 large, dilated at the end. Coracoid large, narrow, aud about half 

 the length of the acromion. Humerus compressed. Radius and 

 ulna not quite so long as the humerus, often united at the ends and 



