18 CALIFORNIA ACADEMY OF SCIENCES. 



Nirmus atopus n. sp. (Plate II, fig. 4). 



From a bird of the cuckoo family (Cuculidse), Piaya 

 cayana thermophila (Panama). This new form is one of 

 the circnmfasciate Nirmi of the general character of 

 Rudow's alchatce (Piaget, Les Pediculines, p. 165, pi. xiii, 

 fig. 12) and allied forms. The few described members 

 of this group have been found on columbine and galli- 

 naceous birds. 



Description of female. Body, length 1.84 mm., width 

 ,63 mm.; abdomen expanding posteriorly to segment 6; 

 pale brownish white with brown lateral abdominal and 

 thoracic bands and circnmfasciate head. 



Head, length .59 mm., width ,53 mm.; forehead 

 broad, rounded in front, with very few very fine hairs 

 on the margin; trabeculse small but distinct, acute; 

 antennae slender, with segment 5 longer than seg- 

 ments 3 or 4; temples rounded, with two long hairs 

 and two or three very fine prickles on margins; eye 

 without a hair, not especially prominent; occipital mar- 

 gin straight, bare; ground color of head whitish with 

 small, inconspicous brown ocular blotches, temples very 

 narrowly margined with brown, and rather broad chitin 

 band, subtranslucent brownish along the entire front 

 and lateral margins of forehead, and ending poste- 

 riorly in small elliptical expansions directed diagonally 

 inwards. 



Prothorax very short, quadrangular; lateral margins 

 straight; posterior angles rounded, with one longhair; 

 posterior margin straight; lateral borders brownish, 

 the coloring extending along the posterior margin of 

 the segment. Metathorax pentagonal, lateral margins 

 bare, posterior margin obtusely angled on abdomen, 

 with one hair in latero-posterior angle and four pustu- 

 lated hairs in two pairs, one pair almost in the latero- 



