44 • NORTH AMERICAN ANOPLURA 



a median group of four, of which the two inner ones are short and flat, 

 and the two outer ones are extremely long and slender, reaching beyond 

 the end of the body, and with two or three very large flat spines in each 

 lateral group. Segments five to seven each with four spines in each me- 

 dian group and two or three in each lateral group. Eight and nine each 

 with median group of two, those of nine being small; and seven and 

 eight each with two long hairs at the posterior angle. There is considera- 

 ble variability in the number and arrangement of the spines, particularly 

 as regards the long hairs on the fourth segment. In some cases there 

 may be three or even four of these, or some of the spines on the third 

 segment may also be elongated. 



On the ventral side the spines are much shorter and broader than 

 on the dorsal side ; segment two with none ; segment three with a group 

 of three on each side ; four, five and six with three or four in the median 

 group and two or three in each lateral group; seven with one median 

 spine. Genital plate and gonapods very similar to those of E. suturalis. 



Measurements of the Male. — Total length .61 mm., length of 

 head .18 mm., length of abdomen .35 mm., width of head .1 mm., width 

 of thorax .16 mm., width of abdomen .33 mm. Resembling the female 

 except that the long hairs on the fourth segment are lacking. Genitalia 

 not differing appreciably from those of E. suturalis. 



Enderleinellus longiceps n. sp. 



Plate II, fig. 5; plate IV, fig. 12; plate VI, fig. 2. 



In the material which we have received from Professor Osborn there 

 are several specimens of an undescribed Anopluran taken from gray 

 squirrels at Lincoln, Nebraska, and with the permission of Professor Os- 

 born we are describing the species. It is closely related to Enderleinellus 

 sphaerocephalus (Burm.), which occurs upon squirrels in Europe; but 

 there are certain very marked differences between the two, the shape of 

 the head and especially the character of the male genitalia distinguish- 

 ing the American species at once. 



Description of the Female. — Total length .51 mm., length of head 

 .14 mm., length of abdomen .33 mm., width of head .8 mm., width of tho- 

 rax .14 mm., width of abdomen .25 mm. 



Head much longer than broad, rather cylindrical in appearance, 

 widest across the base of the antennae. Anterior margin slightly con- 

 vex, lateral margins parallel, nearly straight, temporal angles entirely 

 lacking. A few small hairs on the margin, a transverse row of four, ar- 



