18 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
LIPONYSSUS TRIANGULUS, new species. 
Female.——Medium sized and stout. Palpi reaching the tips of an- 
terior patellae; chelicerae stout, well chitinized. Dorsal shield broad, 
at its widest place over three-fifths as wide as cephalothorax. Peri- 
treme long, slightly smuous and extending to opposite the anterior 
coxae. Sternal plate about as long as broad and reaching the third 
coxae; anterior setae situated just behind the anterior margin; 
middle setae situated on a line between anterior and posterior setae; 
the latter situated at an equal distance from lateral and posterior 
margins. Anal plate triangular (hence name triangulus); and with 
greatest diameter longitudinally, rim uniform and very thick; paired 
setae situated near rim of anus at the posterior margin; caudal area 
extending almost to base of median seta. Legs stout; coxal rings I 
and II, each with chitinous tubercle on inside. Length, 0.63 mm.; 
width, 0.41 mm. 
Male.—Unknown. 
Type locality.—Maryland. 
Type (cotypes).—Cat. No. 24753, U.S.N.M. 
Described from seven individuals taken from King snake, Lampro- 
peltis calligaster, U.S.N.M. No. 61726. 
LIPONYSSUS BACOTI (Hirst). 
Female.—Palpi slender, reaching to about the tips of first femora; 
chelicerae very slender and fitted for piercing chiefly, the cutting 
surfaces being poorly developed. Dorsal shield reduced, at its 
broadest place about one-half as broad as the cephalothorax, behind 
the shoulders the lateral margins are wavy. Peritreme long, slightly 
sinuous, and extending almost to the anterior margin of coxa I. 
Sternal plate extending entirely between the second coxae, its ante- 
rior margin almost straight; front setae situated directly on the 
anterior margin; middle setae situated between front and rear setae, 
the latter being at the apex of posterior angles. Anal plate broadly 
and evenly rounded in front; anus front of middle transverse line, 
rim uniform; paired setae situated at the level of the posterioy margin 
of anus; median seta situated almost twice its length behind the 
anus; caudal area reduced, crescentic and scobinate. Length, 0.78 
mm.; width, 0.56 mm. 
Male.—Notwithstanding a large number of slides of this species 
are in the United States National Museum, no male is present. The 
following facts relative to the male are gleaned from Hirst’s descrip- 
tion: Dorsal shield, ‘‘almost as wide and long as the body, but 
leaving a narrow lateral strip of unprotected integument (except 
anteriorly).’’ The “sternal plate” (holoventral plate) is described as 
follows: ‘Long, narrow, and furnished with eight or nine pairs of 
long hairs and the usual unpaired posterior hair; it is slightly nar- 
