294 NATURAL HISTORY OF ARTHROPODS. 



MALLOPHAGA. 



TMs assemblage of parasitic insects probably forms a part of the order Pseudo- 

 Neuroptera, apparently of about the value of a super-family. Various authors have 

 either placed them with the other Parasita in the order Hemiptera, or have followed 

 Leach in constituting them a separate order under the name Anoplura. 



An undoubted similarity exists between these and the Pediculidse in some of the 

 embryonic stages ; but it is to be noticed that a departure from the hemipterous type 

 occurs near the period of final exclusion from the egg, and that at this time a truly man- 

 dibulate mouth with the valvate labium is acquired, accompanied by corresponding 

 modifications of the associated segments. Accordingly we accept the position given 

 to them by the well-known Neuropterist, Dr. McLachlan, and leave the question of 

 their relative rank to be established by future observation. 



This group is composed of several families, many genera, and hundreds of species 

 of small, or minute, commonly pale horn-colored insects, which undergo an incomplete 

 metamorphosis (the skin being shed in pieces). They are generally detested because of 

 the damage which they occasion to the plumage of birds, or the fur of animals. Every 

 species of bird or beast has one or more kinds of these pests upon some one or other 

 of the regions of its body, while, in a few cases, a single species of bird is known to 

 harbor as many as four or five kinds of these parasites. As all of these forms are pro- 

 vided with jaws, they gnaw the tender cuticle at the base of the hair or feathers, cause 

 intolerable irritation, and, by reason of their great numbers, produce wasting dis- 

 orders or even cause the death of the creatures upon which they congregate. 



These lice are apterous, more or less flattened, long elliptical, lancet-shaped, or 

 broadly ovate, and the head is horizontal, shovel-shaped, and often depressed, wedge- 

 like at tip. They have distinctly jointed antennae and palpi, a prothorax often con- 

 tracted like a neck, a mesothorax of ample proportions (often as wide as the base of 

 the abdomen), fringes of bristles across and on the sides of the face and abdominal 

 segments, spiracles on the upper sides of the body, short, stout legs, placed far out on 

 the sides of the chest, and tarsi with curved, sharp claws. 



Some of the bird-lice, especially such as those which inhabit the Canary bird, the 

 pigeon, etc., are very delicate in appearance, have a translucent outer skin, and move 

 with great celerity between the feathers. The nits or eggs are ovate, and generally 

 glued to the roots of the hairs, or fibres of the feathers, although they may often be 

 found lying loose in the hollow centre of reeds used for perching-sticks in the cages 

 of domestic bii-ds. This is a favorite place for many kinds in winter, giving them an 

 undisturbed shelter and nidus for hatching, and where the minute young ones may 

 sometimes be seen in large crowds. 



Mr. Denny tells us that " having obtained several nits of Scematopimis, JEuryster- 

 nus, and Sitis, and placed the same in a quill which I carried in my waistcoat pocket, 

 from the warmth they thus received I soon became sole projDrietor of a family of my 

 young friends. These I examined soon after their exit from the ova, but could not 

 discover such a difference in their appearance as would have led me to suppose them 

 in the larval state ; the antennae and legs were much thicker in proportion to the bulk 

 of the whole body than when full grown : in fact, they bore pretty much the same 

 resemblance to the mature insect that a lamb bears to the ewe, being ill proportioned 

 in the legs, etc. In point of activity, however, they much exceeded the adults, and 



