nero Species of Lice. 



99 



where the tendon of the large extensor muscle is inserted. 

 The inner third of the base of the mandible is a short 

 rectangular projection. There is a sing-le sharp apex and a 

 series of oblique ridges on the opposable surface. A small 

 plate with a round even margin overlaps the outer edge 

 just behind the apex, giving the appearance of a casque or 

 hood over the outer margin. 



Labium. — The anterior margin is straight, without lobes or 

 prominences. At each lateral angle, set in a dark brown 

 socket of thick chitin, is the so-called paraglossa — a stout 



Fi^. 4. 



-et 



Trichodectes gastrocles, sp. n. Copulatory apparatus, cJ , x 45. 



5P= Basal plate ; ^=Endomere; P=Pararaere; 7'=Deuticle on sac, 

 a. Denticle enlaro'ed. 



single-segmented lobe, tapering slightly at the distal end. 

 Tiie tip of this appendage is obliquely truncate, the outer 

 margin being longer tlian the inner. On the apex pointint>- 

 inwards are four or five minute spines set on relatively large 

 round pedestals. On the ventral surface of the labium 

 between the paiaglossse are eight spines arranged in a circle. 

 Immediately behind this circle is a transverse brown band, 

 which splits into two branches at each end, one running up 

 to the front margin and the other running backwards and 

 disappearing in the clear chitin behind the mouth. This is 

 probably a supporting sclerite for the labium. 



7* 



