ORCELLA. 413 



limb than in Glohicephalus, the proportions of the fingers to one another being much 

 the same as in Orca, there being not that marked difference between the length of 

 the 3rd and 4th finger that distinguishes GloMcephahis. The whole length of the 

 arm from the end of the humerus to the tip of the 2nd finger in the diied limb of 

 a female O. hrevirostris is about one foot, of which the 2nd finger measured 

 from its carpal bone is 6 inches, the humerus being 3"-62, the radius 3"- 50, the ulna 

 3 inches, and the carpus at its middle l"-40. The greatest breadth of the distal end 

 of the humerus is l"-70, and the greatest breadth of the radius l"-80, the combined 

 breadth of the forearm proximally is 3"'32. 



In the carpus four bones are in contact with the ends of the radius and ulna, 

 two in opposition to the former and two to the latter, with another bone opposed 

 to the metacarpal of the 2nd finger. The small bone which is opposed to the 

 outside of the most external of the ulnar bones is evidently the metacarpal of the 5th 

 digit. The bone placed between the end of the radius and the metacarpal of the 

 1st digit is the scaphoid ; the other bone touching the end of the radius and also a 

 portion of the iilna is undoubtedly the intermedium, and the bone on the outside of 

 the ulna the cuneiform or ulnare. Lying between the os intermedium and ulnare is 

 another bone, which also touches the ulna, but which appears from its position 

 to be the cuneiform, although it may probably be of a two-fold origin. There is 

 a large space at the base of the 3rd metacarpal unoccupied by any bone, and which 

 marks the position which the os magnum should have occupied. The bone appHed to 

 the extremity of the second metacarpal is the trapezoid. The manus has thus five 

 bones in the carpus, three belonging undoubtedly to the first and two to the second 

 row. 



In the 1st finger there may be either one or two phalanges, the terminal 

 phalanx being a mere ossicle ; iu the 2nd finger there are five or six phalanges, which 

 are as broad as long ; in the 3rd there are three ; in the 4th two, and in the 5th a 

 phalanx may be represented by a single ossicle or by cartilage only. The metacarpals, 

 five iu number, vary considerably in form. That of the 1st finger is a square- 

 shaped bone ; that of the 2nd is a little longer than broad ; that of the 3rd is 

 twice as long as broad ; that of the 4th has its breadth eqtialling its length ; while 

 that of the 5th is quite as rudimentary as the first bone of the series. 



The pelvic hones. — All the facts which I have been enabled to ascertain regard- 

 ing the pelvic bones of this genus have been already stated under O. fluminalis and 

 in the precediug pages, with the exception that the termination of the intestine 

 lies between the posterior ends of the bones and is attached to them by a strong 

 fascia. There are no accessory bones. 



Skull. — The skull of 0. hrevirostris has been described by Prof. Owen' in 

 detaU. The length of the palatal surface of the maxilla which represents the 

 length of the back of the skull is very slightly shorter, or equal to the interval 

 between the inferior border of the foramen magnum and the posterior borders of 

 the palatal surfaces of the maxUlaries. The osseous beak is slightly contracted a 



' I.e. 



