Art. 19 LICE OF THE GENUS PEDICULUS — EWING 21 



times as long as broad; segment III as broad as long and longer 

 than IV; segment IV broader than long; segment V about one 

 and a half times as long as broad ; segments II, III and IV broadest 

 at distal ends. Macrochaetae of thorax moderate ; second pair 

 slightly longer than the other two; macrochaeta I slightly less 

 than one-half as long as the width of coxa I; macrochaeta III 

 situated about the diameter of thoracic spiracle behind the same. 

 Thoracic spiracles rather small, diameter of spiracular bulb 0.080 

 mm. Abdomen with sharp divisions between segments; about half 

 of the setae of abdomen are arranged in transverse rows, those 

 that are not in rows are smaller; number of setae in transverse 

 row on ventral side of sixth abdominal segment from 7 to 9, average 

 8 (of 10 females examined 8 had 8 setae in this row). Pleural 

 plates similar to those of hmnanus hunianus but less squarish, al- 

 though theie is much variation in their shape. Legs medium in 

 length and stoutness; femur I about one and a third times as long 

 as broad; tibia I fully twice as long as broad. Tubercle on femur 

 III large, its seta not as long as the tubercle itself. In americanus 

 Ihere is a tendency for all the femora to have a posterior tubercle, 

 but those on femora I and II are never conspicuous like the tubercle 

 on femur III. 



Length of average sized, unengorged female, 3.15 mm,; greatest 

 width, 1.00 mm. 



Male. — Leg I stouter than in female. Thumb of tibia I wi^^h 

 spines as follows : Chief spine extending less than one-half its length 

 beyond the margin of the thumb; anterior accessory spine situated 

 but slightly nearer the inner than the outer margin of thumb and 

 not extending beyond the margin; outer posterior accessory spine 

 long, somewhat setiform, and situated as near the outer margin of 

 the thumb as the chief spine itself; inner posterior spine large, about 

 two-thirds as broad as chief spine but longer and situated back from 

 the inner margin of the thumb. Pleural plates similar to those of 

 female, plate I usually somewhat smaller and broader in proportion 

 to its length. Femur III showing a slight tubercular swelling on 

 posterior margin. 

 Length, 2.65 mm.; greatest width, 0.80 mm. 



Type host and type locality. — American Indian mummy from 

 Surco, Peru. 



Type (paratype).— Cat. No. 28107, U.S.N.M. 



Described from males and females taken from the scalps of Ameri- 

 can Indian mummies loaned by the American Museum of Natural 

 History through the courtesy of Dr. Frank E. Lutz. Holotype (a 

 female, deposited in American Museum of Natural History) taken 



from hair of head of mummy yoTni Surco, Peru; nymphs and nits 



