CHAP. XVI. 



GENERAL CHARACTERS. 



condition in some of the lower vertebrates.^ Fig. 85 

 represents the manus in one of its most complete, and at 

 the same time most generalized, forms, as seen in one of 

 the Water Tortoises iyCJidydra serpentina). 



The carpus consists of two principal rows of bones, an 

 upper or proximal row, containing three bones, to which 

 Gegenbaur has applied the terms radiale (r), intermedium (/), 

 and tdnare {u), the first being on the radial or preaxial side 



Fig. 85.— Dorsal surface of the right manus of a Water Tortoise {Chelydra ser- 

 pent hid, after Gegenbaur. u ulna; R radius; ?/ uinare ; / intermedium ; r radiae ; 

 fcentrale; 1—5 the five bones of the distal row of the carpus; ;«i — w5 the five 

 metacarpals. 



of the limb. The lower, or distal, row contains five bones, 

 called cai'pale i, 2, 3, 4, and 5 respectively, commencing on 

 the radial side. Between these two rows, in the middle of 

 the carpus, is a single bone, the centrale [e). 



In this very symmetrical carpus, it will be observed that 

 the radiale supports on its distal side two bones, carpale i 



1 See Gegenbaur, " Untersuchungen zur Vergleirhcnden Anatomie,"' 

 jtes Heft, Carpus und Tarsus, 1864. 



