508 bulletin; museum of comparative zoology. 



plates bisulcate; on anterior tergites also a clearly impressed median 

 longitudinal sulcus. 



Prescuta mostly very short over entire length, a longer one occurring 

 occasionally at irregular intervals. 



Ventral plates with a median longitudinal sulcus extending from 

 anterior margin to caudad of middle where it commonly ends in a 

 weaker transverse furrow. 



Last ventral plate broad; sides straight and strongly converging; 

 caudal margin moderately angularly bent in from ends to middle. 



Ventral pores small and rather sparse; arranged in a very narrow 

 transverse band between middle and caudal margin. 



Coxopleurae each with two large pits of which the inner portion is 

 covered by the last ventral plate. 



First spiracle subverticall\' obo\'ate, the second and third less 

 elongate and the fourth and succeeding ones circular. First spiracle 

 clearly the largest, the others very gradually decreasing in size caudad, 

 the anterior ones being large and the most caudal ones small or 

 minute. 



Anal legs very much longer than the penult. In the male crassate; 

 the femur thickest with the tibia and first tarsal joint a little thinner 

 and the second tarsal joint abruptly much thinner (Plate 3, fig. 3). 

 Armed with a distinct slender claw. Hairs mostly short, sparse. 



Pairs of legs 59-63. 



Length up to 26 mm. 



Localities. — Mexico: Hidalgo, Guerrero Mill (W. M. Mann). 

 Type, M. C. Z. 1723. Mexico: Pachuca (W. M. Mann); Distrito 

 Federal, Esclava (O. W. Barrett) ; four specimens. Type and M. C. Z. 

 1721, 1722, 1724. 



LINOTAENIIDAE. 

 PAGOTAENIA, gen. nov. 



Head small; a true frontal suture not present. Basal plate wide. 

 Prebasal plate not exposed. Dorsal plates not bisulcate. 



Antennae filiform. 



Labrurn free; tripartite. Median piece very large, overlapping 

 the small lateral pieces; conspicuously arcuate with the free caudal 

 border fringed with close set spines across entire width much as in 

 Azathothus. 



First maxillae with coxae completely fused; coxal plate at each 



