538 GEOLOGICAL 8UBVEY OF THE TEBBITOBIES. 



EXPLANATION OF PLATE XII. 

 Streptocephalus texanus Pa^'kard, details. 



Fig. 1. First foot, male from Kansas, X i A. 

 Fig. 2. First foot, male from Texas, X 50 diameters. 

 Fig. 3. Sixth endite of 2d foot, from Texas, x 50. 

 Fig. 4. Sixth endite of 9th foot, from Texas, X 50. 

 Fig. 5. Tenth foot of specimen from Kansas, X 50. 

 Fig, 6. Eleventh foot of specimen from Kansaa, X 50. 

 Fig. 7. End of body of specimen from Kansas, X 30. 



Drawn by the author, with the aid of the camera lucida. 



