• GOAT LICE. 

 Trichodectes limbatus, Gervais. 



Plate VI, Figs. 1-8. 



Bescription. — Trichodectes Umhatus, GervaitJ — the Angora louse — re- 

 sembles T. climax closely, but difiters in specific details. All the brown 

 marking-son 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 dift'erence lies iu the 

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

 the character of the transverse bands of the abdomen of the male; the 

 abdomen of the male being shorter is relatively wider in j)roi)ortion to 

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

 straight and one- third shorter than the three succeeding, which are of 

 nearly equal length and convex anteriorly, concave posteriorly. The 

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

 margin. The e<^g of this species is larger than that of T. sphwroceph- 

 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, iu 

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

 differences of form and color, seem to be specific. 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- 

 })roach 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 aud sides of the 

 goat. It causes much discomfort and scabbiuess 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— ThQ disease caused by these parasites is of that class 

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

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

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

 on tliese animals they may be killed ou them and uot be expected to 

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