ART. 4 



A TICK FROM THE TEXAS PECCARY McINTOSH 



of the well-separated spurs of coxa I; (d) the broad posterodorsal 

 prolongation of the stigmal plate; and (e) the broad, posteriorly 

 rounded shield of the female. 



Table 1. — Shield mva.'nirciuvHts of ciyht male aiid four female speeiinens of 



Derinacentor lialli 



' Slifirhtly deformed. 



" Flat, unengorged. 



2 Engorged. 



■* Newlv emerged. 



The species of the genus Demittcentor reported from Xorth Amer- 

 ica may be distinguished with the aid of the following key : 



KEY TO THE XORTH AMERICAN SPECIES OF THE GENUS DERMACENTOR 



1. Stigmal plate without distinct dorsal prolongation 2 



Stigmal plate with distinct dorsal prolongation 4 



2. Shield conspicuously marked with white albipictus - 



Shield without white rust, or with very little white 3 



3. Stigmal plate with only few (usually 4 to 10) large isolated 



goblets ; males with only 8 impressed lines behind ; no white 



on shield; spurs of coxa I widely separated niteus 



Stigmal plate with many, more crowded, medium-sized goblets ; 

 males with 12 impressed lines behind : shield usually without 

 white; spurs of coxa I close together nigrolineatus 



4. Spurs of coxa I of equal length 5 



Spurs of coxa I of unequal length 7 



5. Spurs of coxa I widely separated ; shield with mostly small shal- 



low punctations; stigmal plate with broad dorsal prolongation halli 



Spurs of coxa I close together; shield with many deep large 

 punctations 6 



0. Cornua of medium length ; stigmal plate with minute goblets, 

 and short, broad dorsal prolongation ; white on male shield ar- 

 ranged more or less in longitudinal stripes variabilis 



Cornua extra long, especially in male; stigmal plate with me- 

 dium-sized goblets and well-developed dorsal prolongation ; 

 white on male shield uniformly diffused, broken by small 

 brown spots and by numerous deep punctations occidentalis 



7. Internal spur of coxa I slightly longer than external spur ; 

 cornua well developed ; shield with mostly small punctations ; 

 stigmal plate with comparatively few goblets and narrow dor- 

 sal prolongation especially long and narrow in male hunteri 



-D. salmoni Stiles, 1910, will key out with D. albipictus. 



