36 



MEGALONYX. 



coliectioh. 

 Owen's. Jefferson's. Wailes'. Dickeson'i 



Lines. 



Lines. 



Lines. 



Lines. 



25 





23 



23 



19 





16 



16 



21 





18 



n 



2t 



26 



26 



28 



20 



15 



11 



16 



26 



23 



21 



21 



24 





25 





18 





16 





19 





18 





Depth of index first phalanx (middle) 

 Length of index first phalanx (side) 

 Breadth of index first phalanx (base) 

 Depth of median first phalanx (middle) 

 Length of median first phalanx (side) 

 Breadth of median first phalanx (base) 

 Depth of annular first phalanx (middle) 

 Length of annular first phalanx (aide) 

 Breadth of annular first phalanx (base) 



Of second phalanges, the collection of Dr. Owen contains those of the index, 

 median, and annular fingers of one side ; the collection of Col. Wailes contains the 

 same three bones; that of Jefferson the index and annular phalanges; and that of 

 Dr. Dickeson, an annular phalanx. 



The annular phalanx is the longest of the three mentioned, but the median- (PL 

 X, Figs. 4, 8) is the most robust, and is the second in length, while the index is, 

 relatively to its length, more robust than the annular. 



The shaft of the second phalanges (Figs. 4, 8) is demi-cylindroid, being flattened 

 below ; and it is longitudinally concave above, but is most so below, from the 

 expansion in the same direction of the extremities. 



The proximal phalangial articulation consists of two vertical concavities, sepa- 

 rated by a median ridge terminating in tubercular extremities. 



The distal phalangial articulation is formed of two convex condyles united in 

 the form of a trochlea. The groove of the latter is bounded above and below by a 

 fossa, to accommodate the last phalanges in their movements. The exterior sides of 

 the condyles are depressed, and are bounded postero-superiorly by an oblique ridge 

 for the attachment of lateral ligaments. 



collection. 

 Owen's. Jefpeeson's. Wailes'. Dickeson's. 



Length of index second phalanx (side) . 



Depth (proximally) of index second phalanx (side) . 



Depth (distally) of index second phalanx (side) 



Length of median second phalanx (side) . 



Depth (proximally) of median second phalanx (side) 



Depth (distally) of median second phalanx (side) . 



Length of annular second phalanx (side) . 



Depth (proximally) of annular second phalanx (side) 



Depth (distally) of annular second phalanx (side) . 



Of the last or claw phalanges, the collection of Dr. Owen contains those of all 

 the fingers except the thumb ; that of Col. "Wailes, those of the middle three 

 fingers ; that of Jefferson, those of the thumb, median, and annular fingers ; the 

 specimen from the cabinet of the New York Lyceum of Natural History, is of the 

 median finger ; and the collection of Dr. Dickeson contains an index and a median 

 ungual phalanx. 



Lines. 



Lines. 



Lines. 



Lines. 



28 



2t 



29 





25 



24 



22 





15 



n 



16 





30 





33 





24 . 





23 





19 





20 





32 



32 



SI 



35 



21 



22 



21 



20 



m 



IH 



n 



19 



