20 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
LIPONYSSUS AMERICANUS Banks. 
Female.—Palpi moderate; chelicerae slender, each with two slender 
arms. Dorsal shield large, broadest over the bases of third legs; lat- 
eral margin behind the shoulders convex. Peritreme sinuous, extend- 
ing to opposite the first coxae. Sternal plate over twice as broad 
as long and extending entirely between the second coxae; anterior 
setae situated directly upon the anterior margin; middle setae situ- 
ated inside of lateral margins and almost directly between the first 
and last setae; last setae situated nearer the lateral margins than the 
middle setae; all sternal setae of moderate length, slender and sub- 
equal. Anal plate rounded in front and about twice as long as broad; 
anus almost circular and with uniform rim; paired setae halfway be- 
tween rim and lateral margin; median seta situated about its length 
behind anus; caudal area small and crescentic. Legs moderate. 
Length, 0.55 mm.; width, 0.39 mm. 
Male.—In Banks’s orignal description the sex of the individuals 
described is not mentioned. ‘The description itself, however, shows 
that females were at hand. On the type slide (marked holotype) 
are six individuals, all females. The male of this species, therefore, 
appears to be unknown. 
Type locality — Washington, District of Columbia. 
Type.—aA single female, the specimen situated by itself at the top 
of type slide, is here selected as type. Taken from arm of person, 
Washington, District of Columbia; on yellow-bellied sapsucker, 
Raleigh, North Carolina, March 23,1895, by H. H. and C. 8. Brimley. 
LIPONYSSUS OCCIDENTALIS, new species. 
Female.—Small, with a large dorsal shield. Palpi moderate; 
chelicerae stout. Dorsal shield extending across the body at the 
shoulders, lateral margins behind the shoulders convex. Peritreme 
very long and very sinuous, reaching the anterior coxae. Sternal 
plate about three times as broad as long, barely reaching the third 
coxae and with posterior margin strongly arched; anterior setae situ- 
ated on anterior margin; middle setae situated on a line between 
the anterior and posterior setae; the latter almost at the tip of pos- 
terior angles. Anal plate egg-shaped in outline; anus small, almost. 
circular, with uniform rim and situated in frent of a middle trans- 
verse line; paired setae situated near the level of the anterior margin 
of anus; posterior setae situated more than its length behind anus; 
caudal area forming a lobelike projection of anal plate. Legs moder- 
ate. Length, 0.61 mm.; width, 0.31 mm. 
Male.—Unknown. 
Type locality.—Montana. 
Type (holotype).—Cat. No. 24749, U.S.N.M. Type specimen the 
one of two contained females, whigh is mounted dorsal side up, with 
