224 BULLETIN 63, UNITED STATES NATIONAL MUSEUM. 



feebly concave. The margins are scarcely arcuate, and converge a 

 short distance from the femoral base ; the anterior margin is dentately 

 laminate at about the junction of the outer fifth and sixth sevenths. 



The grooves of the meso- and metafemora are more or less defined 

 by sharp margins, which converge to become contiguous somev\,^here 

 near the inner third, less frequently near the middle. 



The tibia' are variable. Protibise more or less feebly compressed, 

 obsoletely to distinctly carinate externally ; the external edge scarcely 

 arcuate. The tarsal grooves are sometimes feebly marked and 

 asperate, or at other times quite well defined and more or less gla- 

 brous. The articular cavities are scarcely open, or feebly so at the 

 most. 



The articular cavities of the meso- and metatibia? are usually quite 

 closed. 



The tarsal grooves of the mesotibia' are sometimes defined for 

 nearly the wdiole length of the external surface, floor of each quite 

 flat and more or less glabrous; usually the grooves are poorly defined 

 and asperate. 



The external surface of each metatibia is more or less flattened and 

 the groove generally feebly defined. 



The tarsi vary in stoutness according to the general habitus of the 

 individual. 



In some examples of the typical form the tarsi appear compaI\i- 

 tively longer than in the more robust forma Icevis. In the typical 

 form a protibia is G mm. long and its tarsus 3.5 mm. in length; in 

 forma Imois the protibia is 6 mm. and the tarsus 3 mm. in length. 

 The actual lengths of parts are of no value, but only Avhen taken 

 relatively. 



It appears as if the shortening is done at the expense of the length 

 alone. In the typical form joints two, three, and four are evidently 

 longer than wide; in forma Imvis the same joints are distinctly wider 

 than long. In each instance they are subequal to each other, and 

 combined equal to the length of the fifth. The first joint is about 

 one-half longer than wide. 



In the typical form the protarsi are three-sevenths of their length 

 shorter thau a mesotarsus and in the forma kvris one-third shorter. 



The mesotarsi in the typical form are about one-ninth of their 

 length shorter than a metatarsus — to the unaided eye they appear 

 subequal. Joints two, three, and four are k)nger than wide and 

 slightly decreasing in length in the order named: together they are a 

 little longer than the fifth; fii-st joint about equal in length to the 

 second and third taken together. 



In forma Utms the meso- and metatarsi are subecjual, and the meso- 

 tarsi have joints two to four, inclusive, quite equal. 



