260 



BULLETIN 169, UNITED STATES NATIONAL MUSEUM 



mension of all three specimens of C. encinensls is larger than the cor- 

 responding dimension of any of the seven available specimens of 

 C. montanus. The best single comparison is of the length of Mi, which 

 compares as follows, by Fisher's formula: 



LM„ C. monlanus: N 6 M 3.25] ^ ^ p ^^^ 



LMi, C. encmensis: N 2, M 3.70J 



FiGTJEE 75.— CorJpftaffMS montanus Douglass, U.S.N.M. no. 9334, with parts in outline supplied from 

 U.S.N.M. nos. 9599 and 9685, left lower jaw: a, Crown view; b, internal view. Four times natural size. 



The difference is certainly significant although not great. ^^ 

 Table 60 gives ranges and means for the National Museum speci- 

 mens of C. montanus and corresponding dimensions of the paratype of 

 C. encinensls, Amer. Mus. no. 17074. The material is not sufficiently 

 abundant for the calculation of other statistical constants. 



Table 60. — Numerical data on lower dentition of Coriphagus montanus and C. 



encinensi.s 



Dimension 



WP,-.. 

 LP4... 

 WP4— 

 LMi... 

 WMi.. 

 LM2_.. 

 WMj.. 

 LM3_-. 

 WM3-. 

 LMi_3- 



'J The mean of C. encinensls is only 14 percent greater than for C. montanus, and it is to be stressed that this 

 is not in itself and stated in this way of specific value. The largest specimen of C. montamis is 13 percent 

 greater than the smallest, and the paratype of C. encinensls is only 6 percent larger than the largest of our 

 specimens of C. montanus in this dimension. With large series the two species would doubtless intergrade 

 in size, yet they are certainly distinct. 



