Johnstonianidae — Newell 
455 
seta. Distal portion of tibia curved sharply 
toward median line (Fig. 214); three pairs of 
smooth normal setae plus the greatly en- 
larged bifid distal seta. The latter is marked 
with somewhat irregular longitudinal striae 
(oil immersion, Fig. 212) and the two teeth 
are hollow in the distal half. Tarsus with two 
strongly curved, usually barbed heavy setae 
at base, a solenidion at 0.25 to 0.33 p, one 
terminal and one subterminal eupathid; other- 
wise with five smooth, normal setae. Podo- 
cephalic canals reaching from cheliceral apo- 
demes to, or nearly to, the urpore; a number 
of branches present. 
Chaetotaxy of legs approximately as shown 
in table (s = solenidia, e = eupathida, f = 
famulus, v = vestigial setae, c = companion 
setae, n = normal setae). 
Femora I to III undivided (Figs. 218-220). 
Patella I and II with a vestigial seta dorsally. 
Tibiae with vestigial seta present only on I 
but with numerous solenidia dorsally as 
shown in the accompanying table; normal 
setae also abundant. Solenidion 4 on tibia I is 
longer, larger, and different in structure from 
the solenidia 3 ; moreover it has a companion 
seta at the base. Tarsus I with si at 0.08 to 
O.lOd and a large eupathid at 0.64 to 0.69d, 
each with a companion seta; famulus at 0.24 
to 0.21pd and a second eupathid at 0.91 pd. 
The famulus is borne on a vesicular alveolus 
and is flattened and expanded at the tip (Fig. 
228). Tarsus II with a delicately annulate 
solenidion at 0.34 and a eupathid with com- 
panion seta at 0.65 d. Famulus like that on I 
but at 0A9pd; a second eupathid at 0.90 pd. 
Tarsus III with a single eupathid at 0.91 pd 
but with no other specialized setae. Most of 
the normal setae of the legs are delicately 
pectinate. All tarsi with three claws, the me- 
dian one longer and more slender than the 
lateral ones. 
type locality: Mount Lassen, California, 
in a small cascade stream about one mile 
above Hat Lake; elevation about 7,250 feet 
(holotype male). July 9, 1954, and August 7, 
1955. I. M. Newell, collector. Also collected 
at headwaters of Kings Creek, Mt. Lassen, 
California, August 6, 1955, by the writer. 
remarks: This species can be differentiated 
from L. scutellata , new species, by the much 
larger number of setigerous sclerites on the 
dorsum (L. scutellata : only about 20 dorsal 
and marginal setae), the bifid form of the 
terminal seta of the palpal tibia (L.s.: this seta 
not bifid), and by numerous points of dif- 
ference in the chaetotaxy of the legs which 
will be apparent by a comparison of the tables 
and descriptions given for the two species. 
Lassenia lasseni is definitely a cold-steno- 
thermal species and its distribution is un- 
doubtedly limited by this fact. The larvae are 
parasitic upon small species of Diptera re- 
sembling Drosophilidae, found breeding 
along the banks of mountain streams. They 
are of the self- detaching type. 
The correlation between the larva and adult 
of this species has been established solely on 
the basis of their occurrence at the same local- 
ity. While the correlation is to a certain degree 
provisional, it is reasonably certain that the 
two forms are conspecific. In all, 9 larvae, 6 
nymphs, and 25 adults were collected at this 
location, and there is no indication that more 
than one species is involved in the collection. 
The species is not as common as the above 
numbers might indicate, for this represents 
the total catch of about 15 hours of hand 
collecting over a three-day interval. The adult 
was first collected July 9, 1954, and larvae and 
adults were found August 7, 1955. 
Lassenia spinifera new species 
female: Two specimens available for study 
tr 
n 
fe 
n 
S3 
pa 
V 
n 
S3 
ti 
s 4 v 
c 
n 
Si 
s 2 
e 
ta 
f 
c 
n 
1 
10 
2,3 
1 
8 
12 
1 
1 
1 
16 
1 
0 
2 
1 
2 
50 
3 
10-12 
0 
1 
8 
4,5 
0 
0 
0 
17 
0 
1 
2 
1 
1 
43 
3.4 
9.10 
0 
0 
8 
3 
0 
0 
0 
15 
0 
0 
1 
0 
0 
40 
