AGRICULTURAL, EXPERIMENT STATION. 101 



back into a groove of the thorax and acute behind. Antennae five- 



t jointed, located on the middle and side 



and usually extending- forward. Thorax 

 nearly twice as long as wide, with a 

 breathing pore on the upper side 

 oxjposite each of the second pair of legs. 

 Abdomen oblong, wih nine segments. 

 Devoid of chitinous plates or tubercles 

 at the sides. Clothed, apparently, with 

 small teeth, the outer row giving the edge 

 \V\ 3 II i °^ *^ e kody a finely dentate appear- 

 ~lMj] V^gjJ-^^A ance. The terminal segment bilobed 

 \i^M fix II Y behind, each angle armed with about 



'Tn' 'iWlfl' fi ye rather long hairs. The two or three 



FlG .2 preceding segments bearing, on each 



side, two quite long hairs. The under side of the next to the last 

 abdominal segment bears two brush-like organs. (See Fig. 2.) Gen- 

 eral color, bluish gray in adults. The life history of this species is 

 much like that of the preceding species, though the details are no 

 better known. 



BITING LOUSE OF CATTLE. 

 (Trichodectes scalaris, Nitzsch.) 

 Order Pseudoneuroptera: Family Philopteridae. 

 General Consideration. 



This species of louse belongs to what are usually called bird lice 

 (Mallophagans.) They are provided with mouth parts adapted for 

 biting. They infest birds and animals, feeding upon the hairs, 

 feathers, epidermal scales and waste products of the body of their 

 hosts. They are said to have a suctorial organ and probably at times 

 feed upon the blood. They are wing'less, one family (Philopteridae) 

 having the leg's adapted for clasping and another family (Liotheidae) 

 adapted for running. The bodies are usually horny and much flat- 

 tened. The species are so numerous that there is scarcely a bird but 

 what harbors one or more kinds. Some regard them as essential to 

 the health of the host, that is, mutuals. They probably cleanse and 

 beautify the feathers and remove wastes from the body. They injure 

 animals less seriously than the true suctorial lice, as their principal 

 food is wastes of the body. In great numbers, especially upon ten- 

 der skinned animals, they are a source of much irritation, causing the 

 animals to grow poor and lack vig'or. 



