20 



NORTH AMERICAN ANOPLURA 



Mt., Calif.) ; Sciurus griseus (Inverness, Marin county; Freestone, So- 

 noma county, and Sanhedrin Mt., Calif.) ; Sciurus douglasi mollipilosus 

 (Cazadero, Gualala, Mendocino county, South Yolla Bolly Mt., and San- 

 hedrin Mt.). Professor Osborn has sent us specimens from Tamias stri- 

 atus (Ames, Iowa). 



There is a considerable degree of variation among these specimens, 

 yet they do not seem to represent more than one species. The species is 

 apparently rather close to H. maniculatus (Neumann), the only species 

 of Hoplopleura previously recorded from a Sciurid. It can be distin- 

 guished from the latter by the shape of the sternal plate. 



Fig. 7. — Hoplopleura arboricola n. sp ; ventral side of second and anterior portion of 

 third abdominal segments of female from Eutamias townsendi ocrogenys. 



Description of the Female. — Length 1.00 mm., length of head .17 

 mm., length of abdomen .75 mm., width of head .12 mm., width of tho- 

 rax .17 mm., width of abdomen .42 mm. Head narrow and rather pointed 

 anteriorly, the temporal angles prominent, temporal margins nearly 

 straight and slightly converging, forming a very slight angle with the 

 occipital margin, which is produced into a rather sharp point. A small 

 chitinized area bearing a single hair on each side, just in front of the an- 

 tennae. Several small hairs on the anterior margin, a transverse row of 

 six hairs in front, and a distinct suture just behind the antennae. Three 

 or four small hairs along the temporal margin, and one long hair and a 

 short spine at the posterior lateral angles. First antennal segment rather 

 large ; second slender ; third, fourth and fifth shorter, the fourth with a 

 slight post-axial projection. 



Thorax relatively small, rather hexagonal in shape, wider than long, 

 the V-shaped notch in the anterior margin very deep, the posterior mar- 

 gin of the prothorax with two long, widely-separated hairs. Sternal 

 plate of the shape of an equilateral triangle with rounded angles and 



