224 DESCPJPTIOX OF A SPECIMEX 



3fanus. — That the number and j)osition of the smaller bones of the flipper might be ac- 

 curately determined, I placed the undissected left flipper (after it had been separated from 

 the radius and ulna) upon a large sheet of coarse paper, and traced its outline. I then be- 

 gan to remove the skin from one side, and having determined the positions of the bones, 

 traced each of the larger ones upon the paper with slight notes of the peculiarities. The 

 change in the bones by maceration, scraping, etc., has, of course, greatly altered their out- 

 lines ; but I have been able to identify all the bones of the carpus with great certainty, and 

 though some of the smaller phalanges may have been transposed, yet this (the left) flipper, 

 as now mounted with the bones at the proper distances, may, I think, for aU practical pur- 

 poses be considered absolutely correct. There are six carpal bones, counting one small one 

 on the ulnar side, which is supposed to represent the pisiform bone. The four digits, count- 

 ing from the radial side, contain respectively five, seven, five and three bones. Before dis- 

 section the radial edge of tlie flipper was thick and rounded, while the ulnar was sharp and 

 thin. The thickest part of the skeleton is through the middle finger (which is much nearer 

 the radial than the ulnar border), and the bones become thinner as they recede from this 

 line, but much more so as they approach the ulnar edge. The bones of the carpus are 

 arranged in two rows ; the proximal consists of the radiale, intermedium and ulnare, with 

 the small pisiform beyond. The distal row consists of two ; the trapezoid and the unciform 

 (according to the views of Mr. Flower), situated respectively in front of the intervals on 

 either side of the intermedium. Each bone presents two smooth sides which are free ; the 

 others being rough for the surrounding cartilage. In the radiale and pisiform alone the two 

 smooth surfaces meet in a rounded border, which lies close to the edge of the limb. The 

 bones of the first row decrease regularly in size from the radial to the ulnar side. The 

 trapezoid is the thickest bone in the carpus, and the unciform the one presenting the great- 

 est extent of surface. 



The bones next in order should perhaps be called the metacarpals ; but, except in size, 

 they are in no way different from the phalanges. I observed nothing like an epiphysis. The 

 metacarpals of the index and little finger somewhat overlap the carpal bones of the second 

 row. Those of the two intermediate fingers rest upon the trapezoid and unciform respect- 

 ively. The bases of the metacarpals are thicker than the distal ends. The phalanges of 

 the index differ from all other bones in the hand by a tendency to be slender and cylindri- 

 cal, while the others are flat and broad. 



The flipper of the right side was not dissected with as much care as had been given to 

 the left, which is very much to be regretted, for an additional phalanx was found, and it 

 was not observed whence it came. After studying carefully the appearance of the flipper, 

 and comparing the accounts of the various skeletons in which the number of phalanges has 

 been given, I have decided to place the extra bone on the digit next to the little finger. 

 Thus the formula of the right flipper, l)eginning at the radial border, will be 5, 7, 6, 3. 



It is interesting to notice that all the carpals and almost all the metacarpals and pha- 

 langes of the two sides were so like their respective fellows that, with the exception of 

 a very few of the smallest, the position of any bone of the right flipper could be determined 

 by a glance at the left. 



