Occasional papers of the California Academy of Sciences

OCCASIONAL PAPERS

OF THE

California Academy of Sciences ;>^^.

No. 90^ 43 pages, 128 figures, 5 maps.

THE HARVESTMEN OF FAMILY TRIAENONYCHIDAE
IN NORTH AMERICA (Opiliones)

By
Thomas S. Briggs

Marine Biological Ubor.lory |
LIBRARY
DECS 1971
Woods Hole, Mass.

SAN FRANCISCO

PUBLISHED BY THE ACADEMY

November 12, 19 71

OCCASIONAL PAPERS
OF THE

California Academy of Sciences

No. 90, 43 pages, 128 figures, 5 maps.

The Harvestmen of Family Triaenoychidae
in North America (Opiliones)

By

Thomas S. Briggs

Galileo High School Lux Laboratory, San Francisco
Field Associate, California Academy of Sciences

INTRODUCTION

Several recent collecting trips to the Pacific Northwest
revealed a large number of unusual phalangids , mostly in the
family Triaenonychidae Soerensen. The morphological char-
acters of this family are expanded and clarified by the new
series and will be of value in determining phalangid evolu-
tion. A significant correlation between undisturbed forest
habitat and these phalangids exists.

The order Phalangida is divided into three suborders, the
mite-like phalangids in Cyphothalmida, the typical "daddy-
long-legs" in Palpatores , and the indolent, shorter- legged
phalangids in Laniatores. Of the Laniatores, Triaenonychidae
is one of the most widespread families. Found in temperate
forests throughout the Southern Hemisphere, this family makes
a northern appearance in the forests of western North America
with no known representatives in the tropics. The Triaenony-
chid habitat in North America, except for cavernicolous spe-
cies, is in coniferous forests which have rather cold, moist
winters.

DISTRIBUTION AND TAXONOMY

Early work in this family was compiled and organized by
C. Roewer in his book "Die Weberknechte der Erde" published
in 192 3. At this time Triaenonychids were known from South

CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

Africa, Madagascar, Australia, New Zealand, and Chile, with
three species described from northwestern United States.
They were distinguished from other phalangids by their three
pronged hind claws. Kratochvil (1958) utilized more detailed
studies of the genitalia and found sufficient differences in
structure to distinguish the family Triaenonychidae and two
related families from others at the superfamily level. The
original family character of single posterior claws with a
pair of lateral branches must now be expanded to include
claws with atrophied branches and claws with two pairs of
branches. A reorganized classification of subfamilies by
Forster (1954) now should include a new subfamily.

The family Triaenonychidae is represented in North Amer-
ica by five genera which are chiefly distinguished by signif-
icant differences in the structure of the posterior claws.
One genus (Cyptobunus) is exclusively cavernicolous and has
lateral branches on the posterior claws that have atrophied
or disappeared entirely. This group is isolated in caves of
the Rocky Mountain Cordilleran. The genus Sole rob unus is the
best known of the American Triaenonychids and is established
in spruce-fir forests from southern Arizona to British Colum-
bia with a peculiar hiatus in California. This genus has the
characteristic trifurcate triaenonychid claw with a ventral
tooth on the main prong. Two new genera, Metanonychus and
Paranonychus , will be placed in a new subfamily. They in-
clude a widespread group of darkly pigmented triaenonychids
having two pairs of lateral branches on the main prong of the
hind claws. These phalangids have been taken from the Aleu-
tian Islands to northern California. The fifth genus, Zuma,
has posterior claws similar to those of Sclerobunus but dif-
fers in the structure of the eye tubercle. It is restricted
to dense forests in central California.

Unless otherwise stated, all specimens are deposited in
the collection of the California Academy of Sciences.

Superfamily TRAVUNOIDEA Kratochvil, Balat and Pelikan, 1958
Family TRIAENONYCHIDAE Soerensen , 1886

Anterior margin of scute usually with three projections
flanking chelicerae. Eyes situated on median tubercle. Dor-
sum with five tergal areas bounded by transverse grooves or
rows of tubercles and three free tergites. Ninth tergite
fused to anal plate. Palpi robust, without slender, elon-
gated segments. Claws of third and fourth legs with uniform
central prong bearing four or less lateral spines in adults
and three pairs of lateral spines in juveniles. Pseudo-
nychium, arolium, or scopula not present on claws of adults
or juveniles. Males with musculature in penis which appar-
ently articulates distal process.

NOTE. The subfamily grouping of Triaenonychidae has been
in doubt for many years. The original scheme was based on
the shape of the sternum. Forster (1954) later relegated
sternal differences to the tribal level and established two

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

subfamilies on the basis of the shape of the trifurcated claw
in New Zealand and Australia. The American triaenonychids
also indicate weakness in classifying subfamilies by sterna
because many have shapes that are intermediate in the sternal
classification system. On the other hand, the structure of
the hind claw does reflect a natural division of the family,
so I will adopt the subfamily characters of Forster.

Key to Subfamilies of TRIAENONYCHIDAE

Hind claws with two pairs of branches

on median prong . . PARANONYCHINAE Briggs , new subfamily
Hind claws with one pair or fewer

branches on median prong 2

Hind claws with side branches much

shorter than median prong . . . TRIAENONYCHINAE Pocock
Hind claws with side branches equal in

length to, or longer than, the

median prong SOERENSENELLINAE Forster

Subfamily TRIAENONYCHINAE Pocock

Claws of 3rd and 4th legs with two or less branches on
median prong, branches shorter than median prong. Penes
with relatively complex apical velum, dorsal plate not chi-
tenized and usually reduced. Eggs not observed in care of
adults.

Key to North American Genera of TRIAENONYCHINAE

1. Hind claws without ventral tooth,

branches small or absent Cyptobunus Banks

Hind claws with ventral tooth and

two branches 2

2. Eye tubercle conical, on anterior

margin of scute Zuma Goodnight and Goodnight

Eye tubercle subconical, slightly

recessed from anterior margin .... Sclerobunus Banks

GENUS CYPTOBUNUS BANKS

Cyptobunus Banks, 19 05, Ent. News, vol. 16, p. 251. Roewer,

192 3, Die Weberknechte der Erde , p. 10 7.
Sclerobunus (part), Crosby and Bishop, 1924, Ent. News, vol.

35, p. 109. Roewer, 1931, Zeit. Wiss. Zool. , vol. 138,

p. 15 3. Goodnight and Goodnight, 194 3, Amer. Midland

Nat., vol. 29, pp. 646-647.

4 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

Scute with segmental areas delineated by shallow grooves.
Eye tubercle recessed from anterior margin of scute. Sternum
narrow, with opercular branches. Operculum large. Body with-
out black pigment, integument colorless. Chelicerae with
fixed finger extending beyond movable finger.

Palpi strongly spinose, femur with at least six strong
ventral spines, without sexual dimorphism.

First tarsus with three segments, second with five or
more segments, third and fourth with four segments. Femur
and second trochanter of first legs with elongate ventral
spines. Tarsal claw of hind legs with lateral spines much
reduced or absent, ventral tooth absent. Distitarsus of
first leg with two segments, of second with three segments.
Basal segment of second tarsi longer than remaining segments

combined.

Penis with two apical setae, apical dorsal spur, and
reduced lateral processes on anterior margin. Ovipositor
without setae on ventral lobe.

NOTE. Cyptobunus is not synonymous with Sclerobunus
because, chiefly, significant differences exist in the
second tarsi, hind tarsal claws, and palpal femora. These
genera show a close relationship, however, in the structure
of their genitalia.

TYPE SPECIES. Cyptobunus cavicolens Banks.

Key to the Adults of Cyptobunus

1. Hind claws with two reduced lateral

branches Cyptobunus cavicolens Banks

Hind claws with one reduced lateral

branch

2. Cornea large, retina in place behind

cornea '

. Cyptobunus ungulatus ungulatus Briggs , new species

Cornea small, retina displaced medially .

Cyptobunus ungulatus madhousensis Briggs, new siabspecies

Cyptobunus cavicolens Banks.
(Figures 1-9 . )

Cyptobunus cavicolens Banks, 1905, Ent. News, vol. 16, p. 251
Roewer, 1923, Die Weberknechte der Erde , p. 631.

Sclerobunus robustus , Crosby and Bishop, 1924, Ent. News,
vol. 35, p. 109. Roewer, 1931, Zeit. Wiss. Zool., vol.

138, p. 153.
Sclerobunus cavicolens , Goodnight and Goodnight, 19 43, Amer.
Midland Nat. , vol. 29, pp. 646-647.

MALE. Total body length, 1.94 mm. Scute length, 1.53
mm. Length of eye tubercle, 0.19 mm. Scute width, 1.79 mm.
Length of second leg, 8.30 mm. Width of eye tubercle, 0.23
mm.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 5

Anterior margin of scute smooth, with weak indentations
over chelicerae and weak projections flanking chelicerae.
Scute smooth, no posterior tubercles, without pigmentation.
Tergites without significant tubercles. Eye tubercle small,
abruptly rounded. Eyes with dark, rounded retinas.

Sternum narrow, broadens near operculum. Maxillary pro-
cesses triangular lobes bearing prominent setae. Operculum
large, semicircular, setose.

Palpi with four pairs of spines on tarsus, six or seven
ventral spines on femur, two spines on trochanter.

Tarsal formula 3-5-4-4. Femur of first leg with two long
ventral spines, second trochanter with one ventral spine.
Tarsal claw of hind legs with single prong bearing two minute
lateral scales on opposite sides of midpoint.

Penis with lateral setae on rounded apical process, velum
on dorsal and ventral surfaces a complex, folded tissue. Ven-
tral transverse flange present.

FEMALE. Similar to male. Ovipositor with blunt lateral
and dorsal lobes bearing a few prominent setae.

JUVENILES. Hind tarsi with typical six-branched claws
of Triaenonychidae.

SPECIMENS EXAMINED. Montana, Jefferson County. Females,
males, and juveniles. Big Spring Room and Cathedral Room of
Morrison Cave (Lewis and Clark Caverns), 31 December 1940,
Pletsch, Mills, Pepper et a^^. and 22 February 1941, W. L.
Jellison. Deposited in the American Museum of Natural His-
tory and Montana State University. Known only from Lewis and
Clark Caverns.

Cyptobunus ungulatus ungulatus Briggs , new species.
(Figures 10-18.)

MALE. Total body length, 2.59 mm. Scute length, 2.21
mm. Length of eye tubercle, 0.22 mm. Scute width, 2.18 mm.
Length of second leg, 1.31 mm. Width of eye tubercle, 0.25
mm.

Anterior margin of scute truncate with slight palpal in-
dentation; only a slight central projection exists. Scute
smooth, no posterior tubercles, without pigmentation. Ter-
gites lack tubercles or pigmentation. Eye tubercle small,
abruptly rounded. Eyes with large rounded retinas.

Sternum very narrow, with indistinct broadening at
operculum. Maxillary processes triangular lobes bearing
setae. Operculum large, semicircular, setose.

Chelicerae robust.

Palpi with four pairs of spines on tarsus, anterior pair
of tarsal spines reduced, ten spines on tibia, seven ventral
spines on femur, two spines on trochanter.

Tarsal formula 3-5-4-4. Femur of firs-t leg with two
spines, second trochanter with one spine. Tarsal claws of
hind legs with single prong bearing one minute scale near
midpoint, ectal on fourth legs and mesal on third legs.

Penis with lateral setae on small, circular apical pro-
cess. Ventral transverse flange present.

CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

FEMALE. Similar to male.

TYPE SPECIMENS. Holotype male, allotype female, Model
Cave, near Baker, White Pine County, Nevada, 24 August 1952,
R. de Saussure. Deposited in the American Museum of Natural
History.

Cyptobunus unqulatus madhousensis Briggs, new subspecies.
(Figures 19-25. )

FEMALE. Total body length, 2.6 7 mm. Scute length, 1.91
mm. Length of eye tubercle, 0.17 mm. Scute width, 2.00 mm.
Length of second leg, 8.10 mm. Width of eye tubercle, 0.64

mm. • u 1 •

Anterior margin of scute uniformly truncate, with little
indication of cheliceral sockets. Scute slightly granular,
without pigmentation. Tergites smooth, unpigmented. Eye
tubercle small, abruptly rounded, eyes with interconnected

retinae .

Sternum narrow, broadens near operculum. Maxillary pro-
cesses triangular lobes bearing setae. Operculum large,

semicircular.

Palpi with four pairs of spines on tarsus, anterior pairs
of tarsal spines reduced, ten spines on tibia, seven ventral
spines on femur, two spines on trochanter.

Tarsal formula 3-5 or 6-4-4. Femur of first leg with 3
spines. Second trochanter with one spine. Tarsal claw of
hind legs with single prong bearing one minute ectal scale
on fourth legs and none on third legs.

Ovipositor with setae on lateral lobes, none on dorsal
lobe.

MALE. Not known.

TYPE SPECIMEN. Holotype female. North Madhouse Cave, near
Provo, Utah County, Utah, 27 May 19 65, 7,500 feet, Stan Moul-
ton. Deposited in the American Museum of Natural History.

GENUS ZUMA GOODNIGHT AND GOODNIGHT

Zuma Goodnight and Goodnight, 19 42, Amer. Mus . Novitates , no.
1188. Briggs, 1967, Pan. Pac. Entomol. , vol. 43, p. 89.

Anterior margin of scute linear with short median pro-
jections. Scute granular, areas distinct. Eye tubercle
located on anterior margin of scute, distinctly conical in
shape, eyes widely separate. Sternum narrow, with opercular
branches. Body with black pigment under integument.

Chelicerae with constriction on basal segment. Palpi
with stout spines, femur with three prominent proximal ven-
tral spines, without sexual dimorphism. Tarsal formula 3-
5-4-4. Distitarsus of first leg with two segments, of second
with three. Basal segment of second tarsi shorter than
remaining segments combined. Femur and second trochanter of
first legs with weak ventral spines. Tarsal claw of hind

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

legs with pair of branches, median prong with ventral tooth.
Metatarsi with astragulus and calcaneus.

Penis with two apical setae, sclerotized ventral plate,
distal section without dorsal or lateral processes. Ovi-
positor without setae on ventral lobe, with setae on lateral
lobes .

TYPE SPECIES. Zuma acuta Goodnight and Goodnight.

Key to the Females of Zuma

Adults with yellow-brown integument under-
lain by black pigment, if black pigmenta-
tion diminished, integument colorless.

Low elevation habitat

Zuma acuta Goodnight and Goodnight

Live adults with yellow integument under-
lain by very faint black pigment.
Above 4,000 feet . . . . Zuma tioga Briggs , new species

Zuma acuta Goodnight and Goodnight.
(Figures 26-35.)

Zuma acuta Goodnight and Goodnight, 19 42, Amer. Mus . Novita-
tes , no. 1188. Briggs, 1967, Pan Pac. Entomol. , vol. 43,
p. 89.

MALE. Total body length, 1.9 mm. Scute length, 1.14 mm.
Length of eye tubercle, 0.31 mm. Scute width, 1.3 3 mm.
Length of second leg, 4.27 mm. Width of eye tubercle, 0.27
mm.

Anterior margin of scute with rounded shoulders. Scute
granulate. Integument brownish yellow. Cephalothorax with
intricate pattern of dark pigment. Areas continuously pig-
mented except for four pairs of light lateral spots and light
band between areas four and five. Tergites each with a band
of dark pigment and a pair of light lateral spots. Eye
tubercle conical, large, about one third width of scute at
its position.

Maxillary processes of second coxae lightly setose,
rounded lobes. Operculum barely extends to third coxae.

Chelicerae with base of distal segment setose.

First leg with spine bearing tubercle on first and second
trochanters, two spine bearing tubercles on base of femur.
All legs with dark pigmentation.

Penis with truncated apex and two lateral setae.

FEMALE. Similar to male.

JUVENILES. Hind claws with three pairs of lateral
branches .

NEW RECORDS. CALIFORNIA: Monterey County: Near Pfeif-
fer Falls, Big Sur, 2 July 1967, T. Briggs, T. Lee, and B.
Leong; 3.5 miles east of Highway 1 on Bixby Canyon Road, 9
July 1967, T. Briggs. San Mateo County: 0.7 miles east of

8 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

junction of Cloverdale and Canyon roads, 15 August 1965, T.
Briggs and V. F. Lee; 1.7 miles west of Woodside on King's
Mountain Road, 23 January 1966, K. Horn and T. Briggs; 7 miles
from Cloverdale Road on Butano Creek, 15 August 1965, T.
Briggs and V. F. Lee; 4.0 miles south of junction of State
Highway 35 and Half Moon Bay Road, San Francisco Game Refuge,
15 August 1965, T. Briggs, V. F. Lee, and K. Hom. Santa
Cruz County: Empire Cave, near Santa Cruz, 17 April 1966,
T. Briggs, V. F. Lee, and K. Hom; Empire Cave, 11 June 1966,
V. F. Lee and T. Briggs; Empire Cave, 26 August 1963, R.
Graham. Dolloff Cave, near Santa Cruz, 19 March 1966, K.

Hom.

NOTE. Populations of Zuma acuta found in Empire Cave,
near Santa Cruz, Santa Cruz County show some loss of pig-
mentation. The type is from Redwood City, California.

Zuma tioga Briggs, new species.
(Figures 36-41.)

FEMALE. Total body length, 1.6 8 mm. Scute length, 1.0 6
mm. Length of eye tubercle, 0.19 mm. Scute width, 1.21 mm.
Length of second leg, 4.19 mm. Width of eye tubercle, 0.23

mm.

Anterior margin of scute with rounded shoulders. Scute
with only slight indication of black pigmentation. Integu-
ment yellow. Five bands of faint dark pigment indicate
scutal areas. Scute granulate. Tergites granulate, with
very faint dark pigment. Integument yellow. Eye tubercle
width about one fourth scute width at its position, conical.

Maxillary processes of second coxae lightly setose,
rounded lobes. Operculum barely extends to third coxae.

Chelicerae with base of distal segment setose.

Legs with traces of black pigmentation.

MALE. Unknown, may not exist.

JUVENILES. Hind claws with three pairs of lateral

branches.

TYPE SPECIMEN. Holotype female, 3.8 miles northeast of
Crane Flat Ranger Station, Yosemite National Park, Tuolumne
County, California, 21 July 1968, G. Leung, M. Wong, and T.
Briggs .

OTHER LOCALITIES. CALIFORNIA: Mariposa County: 5.8
miles west of Crane Flat Ranger Station, Yosemite National
Park, 28 July 1967, (7000 feet), T. Briggs. Tuolumne County:
5.0 miles west of Crane Flat Ranger Station, Yosemite Nation-
al Park, 28 July 1967, (5000 feet), T. Briggs and A. Lee;
North Crane Creek Camp, Yosemite National Park, 21 July 19 68,
T. Briggs.

GENUS SCLEROBUNUS BANKS

Scotolemon (part), Packard, 1877, Bull. U. S. Geol. Geogr.

Surv. Terr., vol. 3, p. 164.
Phalangodes (part), Packard 1888, Mem. Nat. Acad. Sci., vol.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

4, p. 48.
Sclerobunus Banks, 1893, Trans, Amer. Ent. Soc. , vol. 20, p.
152. Banks, 1901, Amer. Natural., vol. 35, p. 672.
Roewer, 19 23, Die Weberknechte der Erde , p. 59 6.

Anterior margin of scute linear, with short median pro-
jections. Shoulders with tubercles. Scute granular, areas
distinct. Eye tubercle rounded, recessed from anterior mar-
gin of scute. Sternum narrow, with opercular branches.
Operculum of average size. Body with faint black pigment,
integument deep reddish brown.

Chelicerae with constriction on basal segment. Palpi
with stout spines, femur with three prominent proximal ven-
tral spines. Some species with dimorphic swelling of palpal
femur. Tarsal formula 3-5-4-4. Distitarsus of first leg
with two segments, of second with three. Basal segment of
second tarsi shorter than remaining segments combined. Tar-
sal claw of hind legs with pair of strong branches, median
prong with ventral tooth. Femur and second trochanter of
first legs with stout ventral spines.

Penis with two apical setae, and apical dorsal spur and
apical lateral processes. Ovipositor without setae on ven-
tral lobe, setae present on lateral lobes.

Hind claws of juveniles with three pairs of branches.

TYPE SPECIES. Scotolemon robustus Packard.

Key to the Males of Sclerobunus

1. Palpal femur of males swollen 2

Palpal femur of males not swollen

. . . . Sclerobunus nondimorphicus Briggs , new species

2. Body with only traces of black

pigment .... Sclerobunus robustus robustus (Packard)
Body with areas of black pigment 3

3. Body with much black pigment,

scute more than 2 mm. long

Sclerobunus robustus idahoensis Briggs, new subspecies
Body with moderate black pigment,

scute less than 2 mm. long

Sclerobunus robustus glorietus Briggs, new subspecies

Sclerobunus nondimorphicus Briggs, new species.
(Figures 42-53.)

Sclerobunus robustus (Packard). Banks, 1893, Trans. Amer.
Ent. Soc, vol. 20, p. 152.

MALE. Total body length, 2.76 mm. Scute length, 2.36
mm. Length of eye ti±)ercle, 0.34 mm. Scute width, 2.30 mm.
Length of second leg, 7.80 mm. Width of eye tubercle, 0.34
mm.

10 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

Anterior margin of scute with zero to four pairs of tuber-
cles on shoulders. Scute with integument orange, black pig-
mentation faint to nil. Tergites with pigmentation slightly
darker than on scute, but lighter than other Sclerobunus.
Eve tubercle a rounded mound.

Sternum with median groove. Maxillary processes rounded
and setose. Operculum extends close to third coxae.

Palpi of male not swollen at femur.

First leg with 2 or 3 spines on femur. Penis with scler-
otization at base of apical setae, distolateral velum pro-
jections moderately acute.

FEMALE. Similar to male.

TYPE SPECIMENS. Holotype male and allotype female. a.b
miles northwest of Easton on U. S. Highway 90, Kittitas
County, Washington, 23 June 1966, T. Briggs , V. F. Lee, A.

Jung, and K. Hom. ,„ ^ . ■, *. ^^

OTHER LOCALITIES. BRITISH COLUMBIA; 10.6 miles east of
Hope near Manning Park, 23 August 1969, T. Briggs. 17 8
miles east of Hope near Manning Park, 23 August 1969, T.
Briggs. OREGON: Clackamas County: 3 miles southeast of
Rhododendron, 5 September 19 70, T. Briggs, K. Hom, R. Lem,
W. Lum, and J. Nishio. Clatsop County: 1 mile south of
Saddle Mountain State Park, 2 August 1967, T. Briggs and A.
Jung. Columbia County: 5.5 miles south of Clatskanie, 8
August 1967, K. Hom. WASHINGTON: Grays Harbor County: 6.8
miles south of Neilton, 22 June 1966, T. Briggs, V. F. Lee,
A. Jung, and K. Hom; 20.8 miles east of Queets on Highway 101,
22 June 1966, V. F. Lee, and A. Jung. Jefferson County:
11.5 miles southwest of Hoh Rain Forest Road on Highway 101,

22 June 1966, A. Jung; 1.5 mile northeast of Maynard, 23 _
August 1966, T. Briggs, A. Jung, K. Hom, and V. F. Lee. King
County: 16.4 miles northwest of Hyak on U. S. Highway 90,

23 June 1966, T. Briggs, V. F. Lee, A. Jung, and K. Hom.
Lewis County: Chanapecosh, Mt. Rainier National Park, 8
August 1955, V. Roth.

Sclerobunus robustus robustus (Packard) .
(Figures 54-60.)

Scotolemon robustus Packard, 1877, Bull, U. S. Geol. Geogr.

Surv. Terr. , vol. 3, p. 164. [Type: Southwestern

Colorado; Mus . Comp. Zool. , Harvard.] Banks, 1902,
Proc. Acad. Nat. Sci. Phil., vol. 53, p. 593.

Phalangodes robustus, Packard, 1888, Mem. Nat. Acad. Sci. ,
vol. 4, p. 48.

Sclerobunus robustus. Banks, 1893, Trans. Amer. Ent. Soc. ,

vol. 20, p. 152. Banks, 1901, Amer. Natural., vol. 35,

p. 672. Banks, 1911, Pomona Jour. Ent., vol. 3, p. 416
Roewer, 1923, Die Weberknechte der Erde , p. 59 7.

MALE. Total body length, 3.09 mm. Scute length, 2.44
mm. Eye tubercle length, 0.34 mm. Scute width, 2.35 mm.
Length of second leg, 7.18 mm. Eye tubercle width, 0.38 mm.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 11

Anterior margin of scute with two to four pairs of tuber-
cles on shoulders. Scute with orange integument, black pig-
ment faint. Dark patches at ends of anterior scutal groove
and dark band on each scutal area. Four pairs of lateral
light spots on posterior of scute. Tergites granular with
central band of dark pigment. Eye tubercle a rounded cone
slightly recessed from anterior margin. Median of eye tuber-
cle with light longitudinal band. Eyes joined by dark
retinal pigment.

Maxillary processes acute and setose. Operculum setose,
does not extend to third coxae.

Chelicerae with large dorsal tubercles on distal segment.
Base of distal segment setose. Male palpi with swollen
femur .

First leg with ventral spine on first and second trochan-
ters, two ventral spines on femur.

Penis with dorsal and ventral plates obscured by complex
velum. Distolateral projections from velum spine-like. Ven-
tral transverse groove present.

FEMALE. Palpi with normal femur.

NEW RECORDS. ARIZONA: Apache County: 2.4 miles north
of Alpine on U. S. Highway 666, 18 August 1967, T. Briggs, K.
Hom, and P. Lum. Cochise County: Barfoot Meadows, Chirica-
hua Mountains, 28 July 1963, (8800 feet), V. Roth. Coconino
County: 7 miles north of Flagstaff, San Francisco Mountains,
5 August 1967, D. S. Rentz ; Arizona Snowbowl , Flagstaff, 24
August 196 7, T. Briggs, K. Hom, A. Jung, J. Tom, and P. Lum.
Graham County: Hospital Flat, Mt. Graham, 19 August 1952,
(9050 feet) , H. B. Leech and J. W. Green; Mt. Graham, 19
August 1952, (10,000-10,500 feet), H. B. Leech and J. W.
Green; Hospital Flat, 2 August 1965, H. B. Leech. Pima
County: 30 miles northeast of Tucson, Santa Catalina Moun-
tains, T. Briggs and K. Hom. NEW MEXICO: Los Alamos County:
4.2 miles west of Los Alamos, 15 August 1968, (7,700 feet),
T. Briggs and K. Hom. Otera County: 6.0 miles southeast of
Mescalero, 14 August 1968, (6500 feet), K. Hom; 2 miles west
of Cloudcroft, 14 August 1968, (8000 feet), J. Tom, D. Owyang,
B. Rogers, K. Hom, and T. Briggs. Sierra County: 0.8 miles
east of Emory Pass, 16 August 1968, (8000 feet), T. Briggs,
K. Hom, and D. Owyang.

NOTE. Southern subspecies of Sclerobunus robustus are
found at high altitudes in the fir forests of isolated
desert mountains. The isolated populations are remarkably
undifferentiated, even from northern subspecies.

Sclerobunus robustus idahoensis Briggs, new subspecies.
(Figures 61-66. )

MALE. Total body length, 3.0 3 mm. Seute length, 2.24
mm. Eye tubercle length, 0.35 mm. Scute width, 2.44 mm.
Length of leg, 7.94 mm. Eye tubercle width, 0.44 mm.

Anterior margin of scute with three or four pairs of
tubercles on shoulders. Scute with pattern similar to
Sclerobunus robustus robustus , but with much more black

3^2 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

pigment. Tergites with dark pigment. Eye tubercle a rounded

"'°^''sternum with deep median groove. Maxillary processes
rounded and setose, two dark tubercles are present on some
soecimens. Operculum extends to third coxae.
' Palpi with slightly swollen femur on males.

Penis with distolateral velum projections moderately

scut©

FEMALE. Palpal femur normal.

TYPE SPECIMENS. Holotype male and allotype female. 2.»
miles northwest of Clarkia on State Highway 3 , Shoshone
County, Idaho. 11 August 1967, T. Briggs , K. Horn, and A.

Jung. ^ _ .,

OTHER LOCALITIES. IDAHO: Clearwater County: 6.3 miles
north of Headquarters, 12 August 1967, T. Briggs. Idaho
County: Apgar Campground, Clearwater National Forest, 12
August 1967, T. Briggs. Shoshone County: 17.25 miles south-
west of Little North Fork of Clearwater River on Clearwater
Road, 11 August 1967, T. Briggs, K. Hom, and A. Jung; 6.2
miles southeast of Lolo Pass on U. S. Highway 12, 18 August
1967, T. Briggs and K. Hom.

Sclerobunus robust us glorietus Briggs, new subspecies.
(Figures 6T- 72.)

MALE. Total body length, 2.18 mm. Scute, 1.82 mm. Eye
tubercle length, 0.34 mm. Scute width, 1.82 mm. Length of
second leg, 4.50 mm. Eye tubercle width, 0.35 mm.

Anterior margin of scute with two or three pairs of
shoulder tubercles. Pigmentation darker than Sclerobunus
robustus nondimorphicus but lighter than Sclerobunus robustus
idahoensis. Eye tubercle a rounded cone.
Sternum with median groove. Maxillary processes rounded

and setose. . . v>i,^v

Palpi with swollen femur on males. First leg with black
pigmentation. Penis with distolateral velum pro:ections

sharply acute. . T,^^^^^

FEMALE. Body pigmentation lighter than m males. Palpal

femur normal, -, ■, ^ ^ ,r,^i« a

TYPE SPECIMENS. Holotype male and allotype female. 4
miles southeast of Glorieta Baldy Lookout, Santa Fe County,
New Mexico, 14 August 1968, T. Briggs, K. Hom, and D. Owyang.

PARANONYCHINAE Briggs, new subfamily

Claws of third and fourth legs with two pairs of branches
on median prong. Penis with relatively simple apical velum,
dorsal plate chitenized. Eggs not observed in care of
adults. Setose space between posterior of sternum and oper-
cular opening. Prominent sutures at juncture of fused ster-
nites.

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

13

Key to Genera of PARANONYCHINAE

Hind claws with ventral tooth on

median prong Metanonychus Briggs , new genus

Hind claws without ventral tooth on

median prong Paranonychus Briggs, new genus

PARANONYCHUS BRIGGS, NEW GENUS

Scute with areas clearly delineated, prominent eye tuber-
cle on anterior margin. Sternum broad with parallel sides
and blunt apex. Spiracles exposed.

Palpi weakly armed, palpal spines simple, femur with
missing ventral spines.

Tarsal formula 3-5-4-4. Distitarsi of first legs with
two segments, of second with three segments. Femur of first
leg with one or two ventral spines, second trochanter of
first leg with one ventral spine. Claws on third and fourth
tarsi with two pairs of lateral branches, median prong with-
out ventral tooth. Sexual dimorphism not apparent in palpi
or chelicerae. Gland in tubercle on mesal apex of fourth
coxae.

Penis with sclerotized dorsal process and no ventral
process. Ovipositor with prominent lateral setae, but no
dorsal or ventral setae.

Juveniles with typical hind claws of Triaenonychidae.

TYPE SPECIES. Sclerobunus brunneus Banks.

Key to the Males of Paranonychus

Dorsal process of penis tubular, with

acute apex Paranonychus brunneus Banks

Dorsal process of penis flattened,

with beveled apex

Paranonychus concolor Briggs , new species

Paranonychus brunneus (Banks) .
(Figures 73-80T)

Sclerobunus brunneus Banks, 1893, Trans. Amer. Soc. , vol. 20,
p. 152. Banks, 1911, Pomona Jour. Ent. , p. 597. Good-
night and Goodnight, 1943. Amer. Midland Nat., vol. 29,
p. 6 45. Roewer, 1923, Die Weberknechte der Erde , p. 59 7.

Sclerobunus robustus , Roewer, 1931, Zeit. Wiss. Zool. , vol.
138, p. 153.

MALE. Total body length, 1.95 mm. Scute length, 1.62
mm. Length of eye tubercle, 0.34 mm. Scute width, 1.62 mm.
Length of second leg, 3.60 mm. Width of eye tubercle, 0.32
mm.

14 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

Anterior margin of scute rounded. Scute granular, mot-
tled with dark pigment, areas clearly delineated with furrows
and tubercles, integument yellow-brown. Tergites granular,
dark pigment posterior margin, posterior tubercles present.
Eye tubercle conical, extends over anterior margin of scute,
eyes in dark pigment zones at base. Maxillary processes from
second coxae setose, reduced, widely separated by sternum.
Operculum extends to third coxae, dorsal groove usually pre-
sent.

Chelicerae with short fingers, chelicerae unpigmented.

Palpi reduced, weak spines on tibia and tarsus, femur
with but one ventral spine. Black pigment absent from palpi.

Tarsal claw of hind legs with proximal pair of lateral
spines slightly shorter than distal pair. Black pigment may
or may not be absent from distal end of each leg segment,
tarsi usually lightly pigmented.

Penis without ventral process, dorsal process a narrow,
subtubular spur longer than operculum. Two pairs of short
lateral setae near apex.

FEMALE. Operculum truncate, does not extend to third
coxae. Ovipositor with elongated, acute lobes. Setae pre-
sent only on lateral lobes. Female broader than male.

NEW RECORDS. BRITISH COLUMBIA: 17.8 miles east of Hope,
Manning Park, 2 3 August 1969, T. Briggs ; Garibaldi, 22 August
19 69, T. Briggs; Mt. Seymour Park, 2 3 August 1969, W. Lum and
R. Lem; 4 miles north of Brittania Beach, 23 August 1969, T.
Briggs. ALASKA: Atka Island, 2 8 July 1907, E. C. Van Dyke.
OREGON: Clackamas County: 3 miles southeast of Rhododendron,
5 September 1970, T. Briggs, K. Hom, R. Lem, W. Lum, and J.
Nishio. Columbia County: 5.5 miles south of Clatskanie, 8
August 1967, T. Briggs. Lincoln County: 0.5 miles east of
Cape Perpetua, 7 August 1967, K. Hom. WASHINGTON: Skamania
County: 1.0 miles due north of Swift Reservoir Dam, 21 June
1966, V. F. Lee, A. Jung, K. Hom, and T. Briggs. Kittotas
County: 8.6 miles northwest of Easton, 23 June 1966, K. Hom,
V. F. Lee, and T. Briggs; Hyak , 25 August 19 69, T. Briggs.
Jefferson County: 0.5 miles west of HOH entrance to Olympic
National Park, 21 June 1966, V. F. Lee. ,

NOTES. The record for Paranonychus brunneus from Atka
Island, Alaska, consists of a single female which agrees with
this species. Atka Island, however, may not have had trees
in 19 06 and, therefore, was an unlikely habitat for Paranony-
chus . Juveniles have the typical integument of immature
specimens but are unusual in possessing black pigment beneath
the integument that is normally found in adults. Large num-
bers of juveniles were encountered in many of the collecting
localities .

Paranonychus concolor Briggs, new species.

MALE. Total body length, 1.84 mm. Eye tubercle length,
0.33 mm. Scute length, 1.44 mm. Eye tubercle width, 0.31
mm. Scute width, 1.4 8 mm. Length of second leg, 3.9 4 mm.

Anterior margin of scute rounded. Scute granular, faint-
ly mottled with dark pigment, scutal areas darkest.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 15

Tergites granular, faint dark pigment on posterior margin,
posterior tubercles present. Eye txobercle conical, extends
to anterior margin of scute, eyes in dark pigment zones at
base. Maxillary processes from second coxae setose, reduced,
widely separated by sternum. Operculum extends to third
coxae, without dorsal groove. Integument of body distinctly
yellow.

Palpi reduced, weak spines on tibia and tarsus, femur
with two widely separate ventral spines.

Tarsal claw of hind legs with hind pair of lateral spines
slightly shorter than distal pair. Legs darker than body,
tarsi lightly pigmented.

Penis without ventral process, dorsal process a flattened,
transparent, sclerotized spur about equal to length of oper-
culum. Two pairs of elongate lateral setae near beveled
apex.

FEMALE. Operculum shortened, does not extend to third
coxae. Ovipositor small.

TYPE SPECIMENS. Holotype male and allotype female. 6.6
miles south of Drew along Highway 227, Douglas County, Oregon,
T. Briggs.

METANONYCHUS BRIGGS, NEW GENUS

Scute with areas clearly delineated, rounded eye tubercle
on anterior margin. Sternum narrow, with acute apex, widen-
ing at juncture of second and third coxae and third and
fourth coxae. Spiracles exposed. Integument yellow.

Palpi weakly or moderately armed with compound spines,
femur with normal ventral spines.

Tarsal formula 3-5-4-4. Distitarsi of first legs with
two segments, of second with three segments. Femur of first
legs with one to three ventral spines, second trochanter of
first leg with one spine. Claws on third and fourth tarsi
with two pairs of lateral branches, median prong with a
ventral tooth. Sexual dimorphism exists in some species.

Penis with sclerotized dorsal process which may be
reduced and prominent ventral process bearing aedaegus. Ovi-
positor with lateral setae.

JUVENILES. Hind claws as in typical Triaenonychidae.

TYPE SPECIES. Metanonychus idahoensis Briggs, new
species.

Key to the Males of Metanonychus

1. Dorsal process of penis a sclerotized

spine, apical setae absent 2

Dorsal process of penis a sclerotized

plate, apical setae present 3

2. Dorsal process of penis a minute spine

near apex of ventral process

Me t an ony ch us nigricans nigricans Briggs, new species

16

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

Dorsal process of penis a prominent
spine widely separated from ventral
process

Metanonychus nigricans oregonus Briggs, new subspecies

Ventral swelling or spur on base of

male palpal tarsus

Metanonychus idahoensis Briggs , new species

No ventral swelling or spur on base

of male palpal tarsus 4

Dorsal plate of penis broader than ventral

process and with pointed apex

. . . Metanonychus setulus setulus Briggs, new species
Dorsal plate not significantly broader

than ventral process , apex rounded

or blunt 5

Dorsal plate of penis curves strongly
toward ventral process resulting in
a median separation

. . Metanonychus setulus mazamus Briggs, new subspecies
Dorsal plate flush with ventral process 6

Dorsal plate of penis cleft medially

Metanonychus setulus navarrus Briggs, new siobspecies
Dorsal plate entire at apex 7

Adults small; northern California

. . Metanonychus setulus obrieni Briggs, new subspecies

Adults normal size; Oregon Cascades

Metanonychus setulus cascadus Briggs, new subspecies

Metanonychus nigricans nigricans Briggs, new species.
(Figures 81-867)

I

MALE. Total body length, 1.62 mm. Scute length, 1.44
mm. Length of eye tubercle, 0.23 mm. Scute width, 1.42 mm.
Length of second leg, 4.65 mm. Width of eye tubercle, 0.25
mm.

Anterior margin of scute roionded at shoulders. Scute
granular, mottled with dark pigment, areas clearly delineated
with furrows and tubercles. Tergites granular, with central
band of dark pigment. Integument pale yellow-brown. Eye
tubercle a rounded mound near anterior margin of cephalo-
thorax. Light median stripe on tubercle not continuous.
Maxillary processes from second coxae setose and blunt.
Operculum tangent to third coxae, without groove for penis.

Chelicerae with narrow constriction on basal segment.

Palpi with strong spines on tibia and tarsi, femur with
four to five strong ventral spines.

Black pigment continuous on legs, tarsi with black pig-
ment. Distal branches on hind claws elongate.

Penis with very small, sclerotized dorsal spur near apex.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 17

Ventral transverse flange prominent. Apical pair of setae
absent.

FEMALE. Similar to male in structure. Ovipositor with
reduced dorsal and ventral lobes.

TYPE SPECIMENS. Holotype male and allotype female. 0.4
miles north of Del Norte Coast Redwood State Park, Del Norte
County, California, 25 June 1966, V. F. Lee, A. Jung, and K.
Horn.

OTHER LOCALITIES. CALIFORNIA: Del Norte County: 1.6
miles north of Del Norte Coast Redwood State Park, 25 June
1966, V. F. Lee and A. Jung; 15.8 miles north of Humboldt
County Line on U. S. Highway 101, 30 January 1967, V. F. Lee.
Humboldt County: Near Orick, 18 June 1966, V. F. Lee.

Metanonychus nigricans oregonus Briggs, new subspecies.
(Figures 87-94.)

MALE. Total body length, 1.7 7 mm. Scute length, 1.32
mm. Length of eye tubercle, 0.28 mm. Scute width, 2.56 mm.
Length of second leg, 4.49 mm. Width of eye tubercle, 0.30
mm.

Body mottled with dark pigment. Eye tubercle with light
median stripe nearly continuous, black pigment joins retinae.

Femur of first leg with two to three prominent spines on
femur, one on trochanter.

Penis with dorsal process a recurved spine widely separ-
ated from ventral process.

FEMALE. Similar to male.

TYPE SPECIMENS. Holotype male and allotype female. 0.7
miles due west of Blodgett, Benton County, Oregon, 20 June
1966, T. Briggs, V. F. Lee, and K. Horn.

OTHER LOCALITIES. OREGON: Curry County: 4.5 miles
south of Gold Beach, 19 June 1966, T. Briggs, V. F. Lee, and
K. Horn. Lincoln County: 0.5 miles east of Cape Perpetua on
U. S. Highway 101, 7 August 1967, K. Hom; 7.7 miles northwest
of Eddyville, 20 June 1966, T. Briggs, V. F. Lee, and K. Hom.

Metanonychus idahoensis Briggs, new species.
(Figures 95-104.)

MALE. Total body length, 1.39 mm. Scute length, 1.41
mm. Length of eye tubercle, 0.17 mm. Scute width, 1.13 mm.
Length of second leg, 2.74 mm. Width of eye tubercle, 0.19
mm.

Anterior margin of scute rounded at shoulders. Scute
granular, areas clearly delineated by unpigmented furrows,
integument yellow-brown. Tergites granular, with central
band of dark pigment. Eye tubercle with light median stripe
nearly continuous. Dark retinal pigment joins eyes. Ster-
num narrow, with broadening at juncture of second and third
coxae and at operculum. Maxillary processes from second
coxae setose and acute. Operculum extends over base of third

18 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

coxae, without groove for penis.

Chelicerae with constriction on basal segment.

Palpi with two or three prominent ventral spines on
femur. Ectal spur on base of tarsus.

Dark pigmentation increases distally on legs. Femur of
first leg with one prominent ventral spine, second trochanter
with one, and trochanter with one or two. Hind claws with
equal branches.

Penis with ventral flange and pair of apical setae. Ven-
tral and dorsal plates parallel, truncate at apex.

FEMALE. Similar to male but lacks ectal spur on base of
palpal tarsus. Slightly larger in size.

JUVENILES. Hind claws with three pairs of lateral branch-
es .

TYPE SPECIMENS. Holotype male and allotype female. 2.8
miles northwest of Clarkia on State Highway 3, Shoshone
County, Idaho, 11 August 1967, T. Briggs, K. Hom, A. Jung,
P. Lum, and J. Tom.

OTHER LOCALITIES. IDAHO: Idaho County: Apgar Camp-
ground, Clearwater National Forest, 12 August 1967, T. Briggs.
Shoshone County: 1.5 miles northeast of Little North Fork of
Cleaorwater River on Clearwater Road, 11 August 1967, T.
Briggs; 17.3 miles southwest of Little North Fork of Clear-
water River on Clearwater Road, 12 August 1967, T. Briggs, K.
Hom, and A. Jung.

Metanonychus setulus setulus Briggs, new species.
(Figures 105-108. )

MALE. Total body length, 1.41 mm. Scute length, 1.0 8
mm. Length of eye tubercle, 0.22 mm. Scute width, 1.63 mm.
Length of second leg, 3.16 mm. Width of eye tubercle, 0.25
mm.

Anterior margin of scute rounded at shoulders. Scute
granular, areas clearly delineated by unpigmented furrows,
integument yellow-brown. Tergites granular, with central
band of dark pigment. Eye tubercle a rounded mound at anter-
ior margin of scute. Light median stripe nearly continuous.
Sternum narrow, with broadening at juncture of second and
third coxae and at juncture of third and fourth coxae. Max-
illary processes from second coxae setose and acute. Oper-
culum extends over base of third coxae, without groove for
penis .

Chelicerae with constriction on basal segment.

Palpi with strong spines on tibia and tarsi, femur with
one strong ventral spine.

Femur of first leg with three ventral spines , trochanter
with one. Black pigment nearly continuous on legs. Hind
claws with equal branches.

Penis with dorsal plate broader than ventral process,
apex acute. Ventral flange and pair of apical setae present.

FEMALE. Similar to male structure.

TYPE SPECIMENS. Holotype male and allotype female.
Honeyman State Park, Lane County, Oregon, 20 June 1966,

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 19

T. Briggs and V. F. Lee.

OTHER LOCALITIES. OREGON: Clatsop County: Saddle Moun-
tain State Park, 5 June 1955, V. Roth; 7 miles north of
Nehalem, 26 August 1969, T. Briggs; 2.7 miles north of Cannon
Beach, 26 August 19 69, T. Briggs. Coos County: Bridge, Camp
Myrtlewood, 25 July 1955, V. Roth. Curry County: 4.5 miles
south of Gold Beach, 19 June 1966, T. Briggs, V. F. Lee, and
K. Horn. Lane County: 0.6 miles south of entrance to Honey-
man State Park, 19 June 1966, V. F. Lee; 0.3 miles east of
Highway 101 on Cape Creek Road, near Heceta Head, 3 September
1970, T. Briggs, K. Horn, J. Tom, R. Lem, and W. Lum. Lincoln
County: 7.7 miles northwest of Eddyville, 20 June 1966, V.F.
Lee and K. Hom; 0.5 miles north of Depot Bay, 4 September
1970, T. Briggs, K. Hom, R. Lem, W. Lum, and J. Tom.

NOTE. Northern specimens of Metanonychus setulus setulus
tend to have yellow integument exposed on their movable
tergites.

Metanonychus setulus mazamus Briggs, new subspecies.
(Figures 109-116.)

MALE. Total body length, 1.42 mm. Scute length, 1.12
mm. Length of eye tubercle, 0.17 mm. Scute width, 1.12 mm.
Length of second leg, 2.87 mm. Width of eye tubercle, 0.19
mm.

Penis with dorsal plate curved toward ventral plate
resulting in medial separation; about equal in length to ven-
tral plate and truncate at apex.

TYPE SPECIMENS. Holotype male and allotype female. 1.9
miles east of junction of Interstate 5 and Speaker Road, Wolf
Creek, Josephine County, Oregon, 6 August 1967, T. Briggs.

OTHER LOCALITIES. OREGON. Douglas County: 2.2 miles
south of Canyonville, 6 August 1967, T. Briggs; 6.6 miles
south of Drew, along Highway 227, 18 August 1969, T. Briggs.

Metanonychus setulus navarrus Briggs, new subspecies.
(Figures 117-124. )

MALE. Total body length, 1.16 mm. Scute length, 1.0 0
mm. Length of eye tubercle, 0.18 mm. Scute width, 0.9 3 mm.
Length of second leg, 2.70 mm. Width of eye tubercle, 0.20
mm.

Penis with dorsal and ventral plates parallel and about
equal in length. Dorsal plate with longitudinal cleavage at
apex and lacking in dark pigment.

TYPE SPECIMENS. Holotype male and allotype female. 1.5
miles south of Little River, Mendocino County, California, 3
July 1966, T. Briggs, V. F. Lee, A. Jung,, and K. Hom.

OTHER LOCALITIES. CALIFORNIA: Del Norte County: 15.8
miles north of county line (south boundary) on U. S. Highway
101, 30 January 1967, V. F. Lee.

20 CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

Metanonychus setulus obrieni Briggs, new subspecies.
(Figures 125-128.)

MALE. Total body length, 1.13 mm. Scute length, 0.86
mm. Length of eye tubercle, 0.20 mm. Scute width, 0.88 mm.
Length of second leg, 2.37 mm. Width of eye tubercle, 0.17
mm.

Tergites darkly pigmented.

Penis with ventral dorsal plates parallel, truncate at
apex, and about equal in length.

TYPE SPECIMENS. Holotype male and allotype female. Fort
Dick, Del Norte County, California, 2 July 1966, C. W. O'Brien,

Metanonychus setulus cascadus Briggs, new subspecies.

MALE. Total body length, 1.44 mm. Scute length, 0.9 7
mm. Length of eye tubercle, 0.19 mm. Scute width, 0.97 mm.
Length of second leg, 2.77 mm. Width of eye tubercle, 0.19
mm.

Penis with ventral and dorsal plates parallel, truncate
at apex. Penis similar to that of Metanonychus idahoensis .

FEMALE. Larger than male, operculum shorter than that
of male.

TYPE SPECIMENS. Holotype male and allotype female. 9.0
miles north of Marion Forks, Marion County, Oregon, 27 August
1969, (3,000 ft.) T. Briggs.

OTHER LOCALITIES. OREGON: Clackamas County: 2.5 miles
northwest of Brightwood, 5 September 1970, T. Briggs, K. Hom,
R. Lem, W. Lum, and J. Tom.

FOREST RELATIONSHIPS

All travunoids are basically forest animals and are a
surprisingly good indicator of the health of a for'est. I
have found innumerous times that heavily lumbered forests are
devoid of these arachnids, while adjacent primary stands of
trees support an abundance of specimens. They are uneffected
by a sparse removal of trees , but any forest once cut so only
stumps or less remain of the original trees is not repopulated
with triaenonychids and other travunoids even if a tree farm
stand has replaced the forest for many years. Any forest
lumbered to a succession stage of brushy undergrowth or non-
climax trees does not contain these arachnids. One might
conclude, therefore, that triaenonychids have great difficul-
ty in adapting to changes in their environment.

Good examples of this relationship between triaenonychids
and forest health were observed in comparing lumbered and
unlumbered portions of San Mateo County Memorial Park, Cali-
fornia; Butano Ridge of San Mateo County, California; Honey-
man State Park of Lane County, Oregon; south of Gold Beach,
Curry County, Oregon; and numerous locations in the Olympic

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE 21

National Forest of Washington.

LIVE OBSERVATIONS

Specimens in all stages of development seem to prefer the
undersurface of wood in a moist forest habitat. The only-
feeding record was that of an individual Sclerobunus robustus
robustus devouring a small campodid at time of capture. Spec-
imens of Sclerobunus nondimorphicus were offered to various
reptiles and amphibians, but were rejected.

ACKNOWLEDGEMENTS

I wish to express my gratitude to Vincent D. Roth and
Vincent F. Lee for their help in obtaining references and
specimens, and to Dr. Willis J. Gertsh for the loan of mater-
ial from the American Museum of Natural History. Much of the
tedious field work was done by members of the Galileo High
School Science Club (San Francisco) . Curating was ably done
by Kevin Hom and art work performed by Kevin Hom, Jack Tom,
and Robert Lem.

LITERATURE CITED

KRATOCHVIL, J., F. BALAT , and J. PELIKAN^

1958. Vysledky zoologicke expedice CSAV do Bulharska
(Cast I.). Brnenske Zakladny Ceskoslovenske
Akademie Ved (Prace) , volume 30, pp. 371-396.
FORSTER, R. R.

1954. The New Zealand Harvestmen (Sub-order Laniatores)
Canterbury Museum Bulletin, no. 2, pp. 1-329.

/

22

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

FIGURES 1-9. Cytobunus cavicolens Banks. FIGURE 1,
Dorsum. FIGURES 2-3. Ventral and lateral views of penis,
FIGURE 4. Trochanter to femur of first leg. FIGURE 5.
Lateral view. FIGURES 6-7. Lateral and dorsal views of
hind claw. FIGURES 8-9. Ventral and lateral views of
ovipositor.

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

23

11

16

14

17

15

18

FIGURES 10-18. Cytobunus ungulatus ungulatus Briggs ,
new species. FIGURE 10. Dorsum. FIGURE 11. Lateral view.
FIGURES 12-13. Lateral and dorsal views of hind claw.
FIGURES 14-15. Ventral and lateral views of penis. FIGURE
16. Femur and second trochanter of first leg. FIGURES 17-
18. Ventral and lateral views of ovipositor.

24

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

20

21

22

23

25

FIGURES 19-25. Cytobunus ungulatus madhousensis Briggs,
new subspecies. FIGURE 19. Dorsum. FIGURES 20-21. Lateral
and dorsal views of hind claw. FIGURES 22-2 3. Ventral and
lateral view of ovipositor. FIGURE 24. Lateral view.
FIGURE 25. Femur to +--^'~chanter of first leg.

No . 9 0 ]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

25

29

32

34

FIGURES 26-35. Zuma acuta Goodnight and Goodnight.
FIGURE 26. Dorsum. FIGURES 2 7-2 8. Lateral and dorsal views
of juvenile hind claw. FIGURE 29. Lateral view of ovi-
positor. FIGURES 30-31. Ventral and lateral views of adult
hind claw. FIGURE 32. Venter of ovipositor. FIGURES 33-34.
Lateral and ventral views of penis. FIGURE 35. Lateral view

26

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

36

37

38

39

41

40

42

FIGURES 36-42. Zuma tioga Briggs, new species.
FIGURE 36. Lateral view. FIGURE 37. Venter of ovipositor.
FIGURE 38. Dorsum. FIGURES 39-40. Lateral and ventral
views of adult hind claw. FIGURES 41-42. Lateral and
dorsal views of juvenile hind claw.

No . 9 0 ]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

27

50

53

FIGURES 43-53. Sclerobunus nondimorphicus Briggs, new
species. FIGURE 43. Male dorsum. FIGURE 44. Trochanter to
tibia of first leg. FIGURES 45-46. Lateral and ventral
views of adult hind claw. FIGURES 47-48. Lateral and ven-
tral views of penis. FIGURE 49. Lateral view of male.
FIGURES 50-51. Lateral and ventral views of ovipositor.
FIGURES 52-5 3. Dorsal and lateral views of juvenile hind
claw.

28

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

m-'

■;i^-..

54

;■ : if ^'^ ,.1; ■V;-;^-^^::^]

PV^^S^i,,.

-;:.•: 'rrr^^CiS'Sii^J'^"'" "'

Jt

FIGURES 54-60. Sclerobunus robustus robustus (Packard)
FIGURES 54-55. Lateral and ventral views of penis. FIGURE
56. Male dorsum. FIGURES 57-58. Lateral and ventral views
of ovipositor. FIGURE 59. Tibia to trochanter of first leg.
FIGURE 60. Lateral view of m^le.

No . 9 0 ]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

29

62

FIGURES ;l-66. Sclerobunus robust us idahoensis Briggs,
new subspecies. FIGURE 61. Male dorsum. FIGURES 62-63.
Ventral and lateral views of penis. FIGURES 64-65. Ventral
and lateral views of ovipositor. FIGURE 66. Lateral view
of male.

30

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

FIGURES 67-72. Sclerobunus robustus glorietus Briggs,
new subspecies. FIGURE 67. Male dorsum. FIGURE 6 8.
Lateral view of male. FIGURES 69-70. Ventral and lateral
views of ovipositor. FIGURES 71-72. Lateral and ventral
views of penis.

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

31

74

FIGURES 73-80. Paranonychus brunneus (Banks). FIGURES
73-74. Ventral and lateral views of penis. FIGURE 75.
Lateral view. FIGURES 76-77. Dorsal and lateral views of
hind claw. FIGURE 78. Dorsum. FIGURES 79-80. Ventral
and lateral views of ovipositor.

32

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

FIGURES 81-86. Metanonychus nigricans nigricans Briggs ,
new species. FIGURE 81. Dorsum. FIGURES 82-83. Ventral and
lateral views of penis. FIGURES 84-85. Ventral and lateral
views of ovipositor. FIGURE 86. Lateral view.

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

33

91

94

'^^MM^^'^

FIGURES 87-94. Metanonychus nigricans oregonus Briggs ,
new species. FIGURES 87-88. Ventral and lateral views of
penis. FIGURE 89. Lateral view of male. FIGURE 90. Dorsum.
FIGURES 91-92. Dorsal and lateral views of hind claw.
FIGURES 9 3-9 4. Lateral and ventral views of ovipositor.

34

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

97

98

99

/ ;

100

101

102

103

104

FIGURES 95-104. Metanonychus idahoensis Briggs , new
species. FIGURE 95. Lateral view of male. FIGURE 96.
Dorsum. FIGURES 9 7-9 8. Ventral and lateral views of adult
claw. FIGURES 101-102. Dorsal and lateral views of
juvenile claw. FIGURES 103-104. Lateral and ventral views
of ovipositor.

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

35

108

FIGURES 105-108. Metanonychus setulus setulus Briggs,
new species. FIGURE 105. Dorsum. FIGURE 106. Lateral view.
FIGURES 107-108. Ventral and lateral views of penis.

36

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

m

110

111

109

115

FIGURES 109-116. Metanonychus setulus mazamus Briggs,
new subspecies. FIGURE 109. Dorsiom. FIGURES 110-111.
Ventral and lateral views of penis. FIGURES 112-113.
Ventral and lateral views of ovipositor. FIGURES 114-115.
Lateral and dorsal views of claw. FIGURE 116. Lateral view,

No. 90]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

37

119

120

121

122

123

124

FIGURES 117-124. Metanonychus setulus navarrus Briggs,
new subspecies. FIGURE 117. Dorsum. FIGURES 118-119.
Lateral and ventral views of penis. FIGURE 120. Lateral
view of ovipositor. FIGURES 121-122. Lateral and dorsal
views of claw. FIGURE 12 3. Ventral view of ovipositor.
FIGURE 124. Lateral view.

38

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

126

127

FIGURES 125-128. Metanonychus setulus obrieni Briggs,
new subspecies. FIGURE 125. Dorsum. FIGURES 126-127.
Ventral and lateral views of penis. FIGURE 128. Lateral
view.

No . 9 0 ]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

39

LEGEND

o S.

r. robustus

• S.

r. idahoensis

■ s.

r. glorietus

A C.

u. ungulatus

A C.

u. madhousensis

D C.

cavicolens

MAP 1.
Cytobunus.

Distributions of Sclerobunus robustus and

40

CALIFORNIA ACADEMY OF SCIENCES [Occ. Papers

MAP

2. Distribution of Sclerobunus nondimorphicus

No . 9 0 ]

BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

41

LEGEND

o

idahoensis

•

s. setulus

D

s. cascadus

▲

s. obrieni

A

s. mazamus

▼

s. navarrus

MAP 3. Distributions of Metanonychus idahoensis and
M. setulus.

42

CALIFORNIA ACADEMY OF SCIENCES

[Occ. Papers

MAP 4. Distributions of Me t an ony ch us and Zuma.

No. 90] BRIGGS: NORTH AMERICAN TRIAENONYCHIDAE

43

LEGEND
■ concolor
• brunneus

MAP 5. Distributions of Paranonychus concolor and
P. brunneus.