Hemerotrecha banksi (Muma 1951)
Hemerotrecha californica Banks,
1903: 79; Comstock, 1913: 38 [junior secondary homonym of Cleobis
californica Banks, 1899].
Hemerotrecha banksi Muma, 1951: 99-100, figs 185-192; Muma, 1962:
30-31; Muma, 1970a: 37-38; Muma, 1976: 20; Brookhart and Brookhart, 2006:
319 [replacement name for Hemerotrecha californica Banks, 1903].
Monterey County - Pacific Grove, (Harold Heath), 1 males (holotype). Deposited in the Museum of Comparative Zoology.
Muma, 1951: 99-100, figs 185-192 (as Hemerotrecha banksi):
Total length, 10.0 to 12..0 mm.
Propeltidium 1.2-1.3 1.9-2.2
Coloration in alcohol rusty yellow, with dusky purplish markings as
follows: eye tubercle dark; propeltidium faintly dusky, darker on
anterior margin; mesopeltidium, metapeltidium, and abdominal tergites
dark but scarcely darker than rest of abdomen; venter dark; palpi dark
on tarsi and distal end of metatarsi, faintly dusky on tibiae and
femora; legs dark, lighter on tarsi and metatarsi. Some specimens have
propeltidium, chelicerae, and lighter segments of palpi light, -rusty
yellow with the dusky markings very faint. Malleoli dark on distal
Dentition of chelicerae
variable but following the general pattern shown in figures 185 to 187.
Movable finger with large principal tooth, anterior tooth about half the
size of principal tooth, two intermediate teeth, of which the proximal
is larger, a series of eight to 10 denticules in front of anterior
tooth, and no mesal tooth. Fixed finger broad, undulate, and blunt at
the tip. Fondal notch U-shaped, obscure, and only one-third as wide as
base of fixed finger.
Flagellum complex typical of
group, with dorsal row of five striate bristles tubular except for
apical and subapical bristles which are broad and flattened. Plumose
bristles gently curved ventrally and weakly plumose. Mesal setae of
movable finger plumose except for a few at the distal end of the finger.
Eye tubercle situated on
anterior margin of propeltidium. Eyes separated by one and one-half to
two diameters. Propeltidium wider than long by a ratio of 1 to 1.6.
Metatarsus, tarsus, and tibia
provided with many fine cylinder bristles, but there is no scopula on
the metatarsus. Metatarsus of palpus about 2.5 times as long as tarsus.
First post-spiracular abdominal
sternite provided with two straight, flattened, lanceolate ctenidia
which do not extend the length of the succeeding segment.
Total length, 11.0 to 13.0 mm.
LENGTH WIDTHColoration and markings in alcohol similar
to those of male.
Propeltidium 1.6-2.0 2.7-3.1
Dentition of chelicerae
as shown in figures 190 and 191. Movable finger with large principal
tooth, anterior tooth about half as large as principal tooth, a series
of six or eight denticules in front of anterior tooth, and no mesal
tooth. Fixed finger with principal, medial, and anterior teeth large and
nearly equal in size, two intermediate teeth between principal and
medial and medial and anterior teeth, and two or three denticules in
front of anterior tooth. Supernumerary teeth are common. Fondal teeth
same as in male.
Structure similar to that of
male. Some specimens have two fine, hair-like, trace ctenidia on the
first post-spiracular abdominal sternite which are scarcely
distinguishable from setal clothing. Opercula of genital segment shown
in figure 192.
As Therobates arcellus:
Washoe County - Mercury, 11 July 1960 (Elden Beck), 1 female;
15 July 1960 (Elden Beck), 1 female; 16 July 1960 (Elden Beck), 1 female; 17
July 1960 (Elden Beck), 1 female; 21 July 1960 (Elden Beck), 1 female; 27
July 1960 (Elden Beck), 1 female.