32 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 64, Supplement 1 
Class Diplopoda, millipedes, two pairs of legs per most body rings (fusion of two segments). 
Many cave and eyed forms exist, and are illustrated in Figures 60-66. Millipedes are among the 
most commonly seen members of the cave community, and larva are preyed upon by centipedes in 
some cases (photo). At least six species of large, brown, troglophilic or trogloxenic paeromopids 
are recorded, some up to 150 mm long (Fig. 60). Many millipedes are troglophilic, and there are at 
least 18 troglobitic species from 4 or more orders and 7 or more families. The orders Chordeumat- 
ida and Polydesmida contain the most troglobites. Chordeumatids (Figs. 61-63) are northern in dis¬ 
tribution in the fa mi lies Caseyidae, Conotylidae, and Striariidae. Polydesmids (Macrostemodesmi- 
dae, Polydesmidae, and undetermined) do not occur in Lava Flows North, but in other regions. 
The caseyid Opiona graeningi is known from 11 caves in the Klamath and Marble Mountains 
Region. Most other troglobitic millipedes are known from only a few sites; 11 are single-site 
endemics and 9 are from 2 to 5 sites. 
The largest range for a troglobite in California is that of the conotylid Plumatyla humerosa, 
with 43 known sites in Lava Flows North, in a north-south strip 194 km long and 8-10 km east- 
west (Figs. 5 and 62). The type locality is Sunnyside Mine, excavated in mafic lava in the south¬ 
ern part of the range. Since there is continuous lava throughout its range, it could be a crevice 
dweller also found in caves. The species was taken from wooden mine props throughout the type 
locality, an old placer mine. This species has a reduced number of ocelli (eye spots) and is depig- 
mented. Causey (1961) thought it to be a troglobite that infiltrated the mine from surrounding cav¬ 
ernous limestone, but geologic maps show no limestone within 100 km of the mine, and all occur¬ 
rences of this species are in lava. Shear (1971) reported a population with some morphological dif¬ 
ferences from a lava cave far to the north. Shear (1972) stated that “. . . no other conotylid is as 
strongly modified for cave life.” Nelson and Smith (1976) collected this millipede from a Neotoma 
cinerea nest in a cave in Lava Beds National Monument, and Taylor and Krejca (2006) collected 
it from numerous caves at Lava Beds. Perhaps this species is a relatively recent cave form, and it 
may not have differentiated much from cave to cave. 
The striariid Amplaria shastae, from Ancient Palace Cave and Samwel Cave (type locality), 
Shasta County, has pigmented eyes, is nearly white, has elongated legs and antennae, and a large 
body (a similar species is shown in Fig. 63). These probably are indications of cave adaptation. 
Fossils of this species were found in a Pleistocene stratum in the cave with several extinct mam¬ 
mals. Although Causey thought that the two fossil Julus species described from Samwel Cave by 
Grinnell (1908) may not be the same as this species, Grinnell’s material needs to be restudied as 
indicated by Graham (1960b). 
The first record from a cave in California of the unusual Order Siphonophorida is represented 
by a possible new species of Illacme from Lange Cave, Tuolumne County. The genus contains 
more legs than any other millipede in the world with 318 to 750 legs (Krejca 2009b). 
Colactis utorum (Callipodida, Schizopetalidae) is limited to three sites in the Mojave Desert. 
Shear (1974) described C. briggsi (later syonymized with C. utorum), and speculated that it may 
be troglobitic because of its reduced pigmentation and the harsh desert environment surrounding 
the cave. The species does possess numerous black ocelli, and we consider it a troglophile. Two 
polydesmids and an undetermined species occur in Mojave Desert caves as well. 
Collembolans 
The collembolans (Class Collembola, Figs. 67-69) are known as springtails because of their 
peculiar, spring-like appendage, the furcula, which is folded beneath the body and used for jump¬ 
ing when the animal is threatened. The furcula is held under tension by a small structure called the 
retinaculum and when released, snaps against the substrate, flinging the springtail into the air. 
