(122) 



The main differences between the two forms are as follows : 

 The genal comb consists of six spines in mnrs and of five in ares. The 

 pronotum I)ears in arcs three rows of bristles, the posterior row containing 

 on the two sides together 18 bristles, and the anterior rows together 37, the 

 nnmbers being 17 and 24 in mars. The mesonotum has three rows in mars 

 !ind fonr in ures, both insects bearing additional bristles at and near the base. 

 The metanotnm has three rows in both mars and ares, bnt there are some 

 additional dorsal bristles in ares which are absent from mars. There are two ante- 

 pygidial bristles in nuirs and three in ares. The bristles on the abdomen are more 

 nnmerous in ares than in 7nars, tergite VI having (on the two sides together) a 

 postmedian row of 17 in ares, and in front of it 19 shorter bristles, the numbers 

 being 16 and 13 in mars, on tergite VI ures having 12 and 17, and mnrs 

 Vi and V2. The sternites III to VI bear on each side five bristles in ares 

 and fonr in mars. Tergite VIII has in both forms a straight apical edge, bnt 

 while there are along this edge and near the ventral edge together six long 

 bristles in mars, there are eight or nine in ares. 



One ¥ from Temnco, Chile, taken off Akodon olivaceus by Dr. S. Bnllock on 

 Febrnary 11, 1908. 



Stephanopsylla gen. nov. 



?. Near Stephartocircus Sknse (1890). Helmet not compressed, bnt depressed, 

 being nearly horizontal ; no radiating incrassations ; between the spines and the 

 frontal (npper) edge two rows of small hairs and several long bristles, posteriorly 

 on the nppcrside a nnmber of minnte hairs and on each side a sensory organ (pale 

 dot). Genal comb absent except for the spine-like npper angle of the genal edge. 

 Rostrnm reaching to the ajiex of the forecoxa, the labial palpns consisting of eight 

 segments. Bristles of second antennal segment nnmerous and short ; club nearly 

 twice as long as it is broad. Abdomen with complete combs (in the only species 

 known on tergites I — IV). Basal abdominal sternite with numerons bristles, sternite 

 VII with few bristles. iStylet three times as long as it is broad at the base. Snbanal 

 sensory plate (" pygidium ") with more than forty grooves (44). Anal tergite not 

 divided off by a transverse suture at some distance from the pygidinm. 



Genotype : S. tliomasi Roths. (1903), described as a StephanocircHs. 



