10 PROCEEDINGS OF THE NATIONAL MUSEUM. yol. 63. 



MONOGYROPUS, new genus. 



Tarsus I provided with a single claw. Femur II provided witli 

 a forked and furrowed tenaculum for holding tarsus; femur III 

 normal. Tarsus II with second segment greatly elongated and trans- 

 versely furrowed and with the claw proper, which is greatly reduced, 

 forming a clawlike structure adapted for fitting into femoral tenacu- 

 lum ; tarsus III with second segment clawlike but smaller and with- 

 out transverse furrows. Tibia I without a row of toothlike setae 

 on a swollen or thumb-like expansion at the inner distal margin. 

 A^bdomen elongate, typically each segment with two transverse rows 

 of setae. Sexual dimorphism somewhat marked. 



Genotype and host species. — Gyropus longus Neumann from Abru- 

 coma hennetti. 



Apparently only two species, the genotype and a new species, are 

 included in this genus which is quite distinct on account of the 

 peculiar nature of the last pair of legs. The genital armature of 

 the male is usually large and well chitinized, with an expansive 

 basal plate and strong parameres. 



KEY TO THE SPECIES OF MONOGYROPUS. 



a} Body subrectangular ; sides of abdomen almost parallel; total length over 



IJ mm. M. longiis ( Neumann )r. 



a.'' Body oval ; abdomen swollen ; total length not over 1^ mm. 



M. parvus, new spec-les. 



MONOGYROPUS LONGUS (Neumann). 



Text figs. 1 and 4. 



A long, medium-sized, fairly well chitinized species. Head broad 

 for such a long sj)ecies; temporal lobes slightly projecting and at 

 their angles bearing a tuft of setae; antennal fossae deep, more 

 deeply notched on their ventral than on their dorsal margins; an- 

 tennae of the usual shape being almost capitate. Above, the head 

 is sparsely clothed with setae, including a posterior row of four 

 which are much longer than the others. Prothorax in the female 

 almost as broad as the head and with straight, parallel sides toward 

 the front while toward the rear the sides converge rapidly ; above, the 

 prothorax is provided with several long setae, including two trans- 

 verse rows of four each. In the male, prothorax shorter and on each 

 side armed with a pair of stout, toothlike spines. Mesothorax not 

 so broad as prothorax, and constituting the narrowest part of the 

 body. Metathorax large, shaped like a truncated cone. The ab- 

 domen- in the female much longer than the head and thorax com- 

 bined; in the male about as long. In the female the sides of the 

 abdomen are frequently subparallel, but in the male are more 

 swollen. The abdomen is well clothed with long, stout setae. Geni- 



