GOAT LICE. 



Tkiohodectes limbatus, Gervais. 

 Plate VI, Figs. 1-8. 



Description.— Trichodectes limbatus, Gervais— the Angora louse— re- 

 sembles T. climax closely, but differs in speciflc details. All the brown 

 markings ou T. limbatus are darker and wider; the head is slightly 

 more indented in front ; the dorsal suture (Plate VI, fig. 2 e, e,) is more 

 pronounced; the head is wider in proportion to its length. The banded 

 margin of the abdomen is wider. The greatest difference lies in the 

 disproportion of size between the male and female of T. limbatus, and 

 the charadter of the transverse bands of the abdomen of the male ; the 

 abdomen of the male being shorter is relatively wider in proportion to 

 its length, and has a quadrangular appearance. The first band is nearly 

 straight and oue-th ird shorter than the three succeeding, which are of 

 nearly equal length and convex anteriorly, concave posteriorly. The 

 fourth and fifth segments bear a second narrow band near the posterior 

 margin. The egg of this species is larger than that of T. sphairoceph- 

 . alus or T, climax. 



The marked differences shown between the bands of T. climax and T. 

 limbatus was a constant one in all males examined. This feature, in 

 connection with the difference in size of the eggs and the many minor 

 differences of form and color, seem to be speciflc. The males of these 

 species seem to offer the most tangible characters for separation. When- 

 ever other species of this genus are described particular attention to 

 the males should, on this account, be given. The females seem to ap- 

 proach each other more closely. 



Occurrence and disease. — The goat louse is common, and causes more 

 trouble to goats than the little red-headed louse does to sheep. When 

 present it occurs among the coarse hair along the back and sides of the 

 goat. It causes much discomfort and scabbiness of skin. If the ani- 

 mals are severely infected they become poor and thin. The Angora 

 goat louse caused, in the single flock in which it was seen, not only a 

 severe scabby skin disease, but a loss of fleece. The whole back, sides, 

 and head seemed to be completely covered with the parasites, young 

 and old, and nits. 



Treatment. — The disease caused by these parasites is of that class 

 which is preveutible, and it is inexcusable if it be allowed to continue. 

 The history in each case is that of infection from other sheep, goats, or 

 Angoras, as the case may be. As the parasites spend their whole lives 

 ■oa tUftse animals they may be killed on them and not be expected to 

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