126 



REPORT 108, U. S. DEPARTMEXT OF AGRICULTURE. 



from the pigeon and blue heron, wliile ]\Ir. Beebe has recorded a similar form from 



various birds in the New York Zoological Park. This latter form is supposed to 



have caused the death of a number of birds. 



In Pteralloptes the males have the third legs but little larger than the front legs 



and ending in a sucker. They have usually been taken from tropical birds. 



In Pteronyssus the male has the third pair of legs much longer than the fourth, 



which is very small. The tip of the abdomen is nearly truncate in both sexes, but 

 in the male there is often some indication of two lobes. 

 Three species have been described from Canada: Pt. sim- 

 plex Haller, on the red -breasted woodpecker; Pt. spedosus 

 Tyrrell, on the sapsucker, and Pt. tyrrelli Canestrini (fig. 

 256) (fuscus Tyrrell) on the white-breasted swallow. One 

 species, P. bifurcatus Hall, has been described from Cali- 

 fornia. Megninia is similar to Pteronyssus, but there are 

 several spines near the tip of the third legs, and the tip 

 of the male abdomen is distinctly bifid. They are usually 

 brown in color, and many species are known. Several are 

 described from our birds, as follows:^ M. aculeatus Haller, 

 on the blue jay; J/, tyrrelli Haller, (fig. 254), on the cat- 

 bird; M. gladiator Haller, on the wild pigeon; M.forcipatus 

 Haller, on sandpipers ; M. pici-majcris Buchholz, on the big 

 sapsucker, and M. alhidus Tyrrell (fig. 255), on the white- 

 breasted swallow. 



In Analges the male has the third pair of legs not only 



longer than the others, but usually very much enlarged in the middle, sometimes 



enormously so. On legs I and II there are one or two spurlike projections from the 



tibige and tarsi, and on the base of the femur there is a reflexed spur, the olecranon 



process. The tip of the male abdomen is often pointed and never deeply bilobed; 



the female has a rounded tip and 



elongate body. The tarsal suckers ^.^^rr^W^z^y^^^^ 



are smaller than in Megninia and 



Pteronyssus. Five species have been 



described from American birds: A. 



tyranni Tyrrell, on the kingbird; A. 



longispinosus Tyrrell, on the snow 



bunting; A. tridentulatus Haller, on 



the homed lark; A. cremidonotus 



Trouessart, from California; .1. digitatus Haller, on the Canadian warbler; and the 



European A. passerinus (figs. 252, 253) Linnceus, recorded from several small birds. 



Fig. 259.— Rivoltasia bispinosa. 

 (Original.) 



Fig. 



-Schizocarpus mingaudi: Female, side view. 

 (Author's illustration.) 



Family LISTROPHORID^. 



The membersof this family ("Sarcoptides gliricoles " of ]\I(5gnin) arc closely related 

 to the bird mites, but live upon many of the smaller mammals, including bats. From 

 their habits they are known as "hair-clasping mites." They are small, soft-bodied, 

 and with short and stout legs, terminating in a sucker and often a slender claw. The 

 body usually tapers a little behind, and the legs are widely separate, one from the 

 other; sometimes each pair is at an equal distance from the adjoining ones. The 

 dorsum has a few short hairs, with longer ones at tip. The surface is usually trans- 

 versely striate. The rostrum or beak forms a distinct cone on the front of the body; 

 the palpi are simple, filiform, and lie close to the underside of the beak; they are 



1 Several of these species, natnoly, those rtescrlbod by Prof. Flaller in the Zoitschr. f. 

 wiss. Zoolotrie, 1882, are not mentioned in Prof. Canestrini's treatment of the world 

 species in Das Tierreich, Lief. 7, 1S99. 



