'20-2 Proceedings Port. Soc. Nat. Hist. 



Subspecific Characters : One of the largest of the Microtus 

 pennsilvanicus group. Tail very long, ears prominent, bullae 

 very large and ' globular, palatine foramina markedly broad and 

 bottle- shaped, Coloration as in M. p. pennsilvanicus, except 

 perhaps slightly darker. 



Measurements of Adults. 



Microtus p. shattucki: Total length, 176 to 198: Tail, 54 

 to 62 : Fore foot, 12 to 13 : Ear, 12 to 18. 



* Microtus p. pennsilvanicus: Total length, 167 to 171: 

 Tail, 44 to 46. 



Measurement of Young. 

 Microtus p. shattucki. 



Total length, 136 to 165: Tail, 46 to 53: Fore foot, 11 to 

 12: Ear, 12 to 15. 



* Taken from Elliot's "Mammals of North America," etc. 



(Printed December, 31, 1901.) 



