12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.80 



postero-lateral seta on its side; in front of each pseudostigma is a 

 posteriorly concave, crescentic slit; pseudostigmatic organs minute, 

 simple, vestigial. Eyes lacking. Dorsal abdominal setae about 36, 

 of which 20 are arranged into two transverse rows of 10 each, all 

 short and strongly pectinate. Legs short, last pair longest. Tarsus I 

 with dorsal spine situated almost twice its length from base of segment 

 and with a simple subapical seta. 



Length, of unengorged specimen, 0.17 mm. ; width, 0.13 mm. 



Type host. — Short-tailed shrew {Blarina hrevicauda) . 



Type locality. — Washington, D. C. 



Type 5^^■6?e.— U.S.N.M. No. 1018. 



Described from many specimens taken from Bloerina hrevicauda^ 

 Eock Creek Park, Washington, D. C, collected by J. C. Jones, some 

 on September 18 and some on September 20, 1929. Also from one 

 specimen of Peroviyscus leucopus taken at the same place by the same 

 collector, on September 20, 1929. 



TROMBICULA DUNNI, new species 



Plate 1, Figure 2 



Palpi large, not elbowed, second segment broadly rounded on out- 

 side; first seta with two to four barbs; second seta with one barb; 

 third seta with two to three barbs. Palpal thumb small ; palpal claw 

 usually bifurcate, with a very large, curved, inner prong and a 

 smaller, shorter, almost straight, outer prong; traces of a smaller, 

 inner third prong sometimes seen. Chelicerae strongly curved. 

 Dorsal plate broader than long, front margin slightly incurved on 

 each side of median seta, posterior margin broadly but not evenly 

 outcurved; pseudostigmata situated far from each other and about 

 halfway from the anterior to posterior margin of dorsal plate; 

 pseudostigmatic organs long, slender, setiform, simple. Immediately 

 behind each pseudostigma is an indistinct straight slit or line. Eyes 

 double but corneas of posterior ones lacking, situated about one and 

 a half times the diameter of the cornea of one of the anterior eyes 

 from the lateral margins of the dorsal plate. Dorsal abdominal setae 

 20, arranged in irregular transverse rows as follows: 1-6, II-6, III-4, 

 IV-4. Legs medium, second pair the shortest ; tarsus I with dorsal 

 spine situated about one and a half times its length from base of 

 segment, subapical seta about twice as long as dorsal spine. 



Length of unengorged larva, 0.16 mm.; width, 0.11 mm. 



Type host. — An agouti {Dasyprocta punctata nuchalis). 



Type locality. — Chiriqui, Panama. 



Type slide.— V.S.'^.M. No. 1019. 



Described from several specimens taken from type host. Camp 

 Pital, Chiriqui, Panama, October 26, 1929, by L. H. Dunn and from 



