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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. C yptobunus 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.) 

Scoto lemon 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 
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 ] 



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 ] 



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 ] 



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 ] 



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 ] 



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.