THE GENUS LEBERTIA. 513 



0-110, 0*143 and the terminal segment 0034 mm. It will be 

 observed that the third segment is a little longer than the 

 second. The second and third segments are minutely porose, 

 but the fourth is not. The distribution of bristles agrees fairly 

 well with that of the allied species, but it is to be noted that 

 those on the extensor surface of the first and second segments 

 are stronger, while the bristle on the flexor surface of the 

 second segment is very long and fine, and is curved upward. 

 The striking characteristic of this species is to be noted slightly 

 in advance of the middle of the flexor surface of the fourth 

 segment in the shape of three fine pores with minute setae, 

 whence the specific name of trisetica. 



The epimera are strongly developed with thick sutures, and 

 the inner posterior corners of the fourth pair almost rectangular. 

 The genital area is about 0*22 mm. in length, with about one- 

 fourth projecting posteriorly beyond the epimera. The inner 

 edges of the valves have about twenty fine hairs distributed 

 along their length. The acetabula are long, particularly the 

 two anterior pairs. 



The anus lies near the posterior body margin, and is sur- 

 rounded by a stout ring. The gland pores on each side stand out 

 conspicuously, as well as those at the posterior inner corner of 

 the fourth pair of epimera. 



The species was described from material taken in Surrey 

 in 1896, and so far it has not been recorded from anywhere else. 



DESCRIPTION OF PLATES. 



Plate 33. 



Fig. 1. L. porosa. Dorsal surface, x 22. 



2. L. porosa. Epimera of adult, x 66. 



3. L. porosa. Epimera of nymph, x 66. 



4. L. porosa. Larva, ventral surface, x 94. 



Plate 34. 



Fig. 1. L. tau-insignita. Ventral surface, x 26. (After Sig 

 Thor.) 



2. L. tau-insignita. Genital area, x 80. (After Sig Thor.) 



3. L. tau-insignita. Inner side of left palp, x 133. (After 

 Sig Thor.) 



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