PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES

Vol. 42, No. 11, pp. 315-322, 5 figs. June 24, 1981

STUDIES ON CAVE HARVESTMEN OF THE CENTRAL SIERRA NEVADA WITH DESCRIPTIONS OF NEW SPECIES OF BANKSVLA

By Thomas S. Briggs Research Associate, Department of Entomology, California Academy ofSciences, San Francisco, California 94/18

and

DarreD Ubick Biology Department, San Jose Stale University, San Jose, California 95//4

ABSTRACT: New ecological and biogeographic information on Sierra Nevada cave harvestmen iD Banksula was obtained while environmental impact and mitigation work was being done for the Army Corps of Engineers New Melones Dam project. Isolation appears to be tbe principal factor leading to speciation in Banksula. but the distribution or species in the vicinity of the New Melones Reservoir is not readily explained. Four new species of Banksu'" are described: B. rudolphi, B. martinorum, B. grubbsi, and B. elUolti.

INTRODUCTION 1975 when a mine tunnel in limestone was se­ Troglobitic organisms are scarce in California lected for transplanting biota, including Bank­ caves, possibly due to the relatively small size sula grahami and B. melones, from McLean's and geologic youth of these habitats. Laniatorid Cave, the largest of the threatened caves. As harvestmen of the genus Banksula are distinc­ additional workers transplanted and tive because they are relatively abundant obli­ plant life from McLean's Cave and studied other gate cavernicoles of the Calaveras Formation of nearby caves, some distributional, behavioral, the Sierra Nevada. Intensive coUecting by bio­ and ecological information were obtained which speleological investigators contracted by the allow us to present some biogeographic discus­ Army Corps of Engineers, the Fish and Wildlife sion of Banksula. Service, and the Office of Endangered Species Briggs (1974) reviewed and expanded the ge­ has yielded numerous new records and four new nus Banksula and described four species with species of Banksula. Project teams worked pri­ functional eyes. He showed that the single pre­ marily in the vicinity of the New Melones Res­ viously known species, Banksula californica ervoir site on the Stanislaus River, Calaveras (Banks), lacked corneas and retinae. His con­ and Tuolumne counties, where several caves are tention that all Banksula are confined to caves threatened by completion of the New Melones is supported by all subsequent investigations. Dam. Biological surveys were begun in May Only Banksula melones, which has relatively [315J 316 PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES, Vol. 42, No. 11 BRIGGS AND UBICK: CAVE HARVESTMEN 317

well-developed eyes, has been collected near or nose tubercle on patella; retinae incom- at the cave twilight zone. Sita/cina sierra Briggs plete or absent; corneas present 6 and Hom is the only laniatorid harvestman 5a. Submarginal row of tubercles on eighth found in epigean habitats adjacent to cave lo­ tergite and last sternite ._ calities. ______.. B. rudo/phi new species

METHODS AND DEPOSITION 5b. No submarginal rows of tubercles on ter- gites or sternites . o The structures measured and morphological ______._. B. martinorum new species terminology used in this paper are generally 6a. Eye tubercle a rounded cone; small spur those described by Briggs (1968) for laniatorid ectal to proximal ventral spine on palpal harvestmen, with one modification that appears femur; incomplete retinae usually pres- in this paper and in Briggs (1974): we substitute enL ... B. tuo/umne Briggs "second endites" for that portion of the second 6b. Eye tubercle obliquely truncate in lateral coxae previously referred to as the maxillary view; no spur ectal to proximal ventral processes. Another structure, the labial process, spine on palpal femur; retinae absent _ first described by Briggs (1971), is located be­ ------. B. grubbsi new species tween the second endites. Unless otherwise noted, all specimens record­ 7a. First legs longer than 4 mm; retinal di­ ed in this paper were preserved in ethyl alcohol ameter greater than 0.03 mm; aedeagus • californica .. galilei and are deposited in the collection of the Cali­ and enclosing sheath fold anterior to re- • grahami fornia Academy of Sciences. curved prongs of dorsal plate . ______. B. me/ones Briggs • melones • luolumne • Key to the Species of Banksu/a 7b. First legs shorter than 4 mm; retinal di­ o elliotli ameter less than 0.03 mm or missing; ae­ 6 grubbsi la. Operculum small, held almost entirely be­ o marlini • tween mesal margins of fourth coxae; deagus and enclosing sheath held within o rudolphi bifurcate dorsal plate 8 males with apex of aedeagus not enclosed t-1f~ I::;",,_~ Columbl8 in sheath, velum on dorsal plate smooth 8a. Eye tubercle and elevated area behind (ca/ifornica group) 2 .- without tubercles; retinae present _ lb. Operculum large, with posterior margin FIGURE I. Map showing counties in the central Sierra Nevada where Banksula have been collected. The inset shows the ______. B. grahami Briggs region along the Stanislaus River where environmental impact and mitigation work on Banksula has been concentrated. well behind mesal extreme of posterior 8b. Eye tubercle and elevated area behind tu- margin of fourth coxae; males with apex berculate; retinae reduced or missing _ of aedeagus enclosed in sheath, velum on ______. B. el/iotti new species sternite with two rows of tubercles. Anal plate holotype. Proximal ventral spinose tubercle on dorsal plate in transverse folds (me/ones group) ._.______7 with medial tubercles. Second endites with con­ palpal tibia present, equal in size to robust ven­ Banksula rudolpbi new species cave ectal margin. Labial processes rounded. tral spinose tubercle on palpal patella. Opercu­ 2a. Retinae entire; eye tubercle obliquely (Figure 2) Operculum with narrow, rounded anterior; pos­ lum with truncate apex (rounded in some indi­ truncate in lateral view B. ga/i/ei Briggs HOLOTYPE.-Male. Body length 1.67 mm; terior margin adjacent to mesal extreme of pos­ viduals); posterior margin behind mesal extreme 2b. Retinae absent or incomplete; if retinae scute length 1.40 mm; scute width 1.14 mm; eye terior margin of fourth coxae. of posterior margin of fourth coxae. present, eye tubercle a rounded cone ._ 3 tubercle length 0.23 mm; eye tubercle width 0.28 Palpal femur with six prominent proximal dor­ TVPE-SPECIMENS.-Holotype, allotype, 21 paratypes (9 O. mm; operculum length 0.18 mm; operculum sal spines (some individuals with only five 3a. Small spines or tubercles between prin­ 9 9,3 juv.): Chrome Cave, near Jackson, Amador County, width 0.21 mm. spines) and one small distal dorsal spine; no se­ cipal dorsal spines on palpal femur; cor- California, 5 ApT. 1979, D. C. Rudolph, S. Winterath, and B. Palp: trochanter 0.19 mm, femur 0.79 mm, tae or tubercles between dorsal spines; ectal Martin. Paratypes, 2 0, 2 9,3 juv.: same locality, 21 Sep. neas absent B. ca/ifornica (Banks) patella 0.44 mm, tibia 0.65 mm, tarsus 0.44 mm. spur at base of first ventral spine small and 1980, T. S. Briggs and D. Ubick. Paratype, I 0: same locality, 3b. No small spines or tubercles between Leg 11: trochanter 0.19 mm, femur 1.42 mm, rounded; venter with numerous small tubercles. 24 Jan. 1981, T. S. Briggs and D. Ubick. principal dorsal spines on palpal femur; corneas present or absent __ .______4 patella 0.44 mm, tibia 1.26 mm, metatarsus 1.02 Proximal ventral tubercle on palpal tibia re­ ETYMOLOGY.-This species is named for mm, tarsus 1.58 mm. duced, spine from tubercle absent. Ventral spine biospeleologist D. Craig Rudolph. 4a. Proximal ventral spinose tubercle on pal­ Scute with segmentation delineated by tuber­ on palpal patella arising from a reduced tubercle. ECOLOGICAL NOTEs.-Chrome Cave is a small pal tibia equal to ventral spinose tubercle cles, eye tubercle and area behind tuberculate. Tarsal formula 4-6-5-6. cave situated in about 0.02 km2 of limestone. on patella; retinae absent; corneas pres- Eye tubercle a rounded cone without retinae Body concolorous yellow-orange. The outcrop is surrounded by serpentine which ent or absent . .. 5 (some individuals also without corneas). Ter­ Penis typical of ca/ifornica group (see Briggs also forms much of the cave's walls. The hu­ 4b. Proximal ventral spinose tubercle on pal­ gites with row of tubercles at margin, eighth ter­ 1974: 11-12). midity is relatively high and a mean temperature pal tibia always smaller than ventral spi- gite also with medial row of tubercles. Posterior ALLOTYPE.-Female. Slightly smaller than of 18 C was recorded on 24 January 1981. Bank- 318 PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES, Vo!. 42, No. II BRIGGS AND UBICK: CAVE HARVESTMEN 319

FIGURE 3. Banksu/a martinorum Briggs and Ubick, new species. Lateral view of body and left palpus of male holotype.

Banksula grubbsi new species TVPE-SPECIMEN.-Holotype: Black Chasm Cave, near Vol­ (Figure 4) cano, Amador County, California, 19 Feb. 1978, A. G. Grubbs. HOLoTYPE.-Male. Body length 1.49 mm; scute length 1.26 mm; scute width 1.23 mm; eye FEMALE.-Unknown. tubercle length 0.25 mm; eye tubercle width 0.35 ETYMOLOGY.-This species is named for FIGURE 2. Banksu/a rudo/phi Briggs and Ubick, new species. a. Lateral view of body and left palpus of male holotype; b. mm; operculum length 0.18 mm; operculum biospeleologist Andrew G. Grubbs. Lateral view of left palpus of female allotype. width 0.21 mm. Palp: trochanter 0.19 mm, femur 0.70 mm, Banksula elliotti new species patella 0.39 mm, tibia 0.53 mm, tarsus 0.65 mm. sula rudolphi is found throughout the upper re­ retinae or corneas. Tergites with submarginal (Figure 5) gions of the cave, predominantly on the under­ row of tubercles. Second endites large, ectal Leg 11: trochanter 0.18 mm, femur 1.49 mm, sides of rocks. Associated with Banksula is a margin slightly concave. Labial processes with patella 0.44 mm, tibia 1.23 mm, metatarsus 0.96 HOLOTYPE.-Male. Body length 1.61 mm; rich assortment of predators, of which spiders acute anterior margin. Operculum with rounded mm, tarsus 1.49 mm. scute length 1.23 mm; scute width 1.28 mm; eye (Araneae) are most abundant. We recorded the anterior, posterior margin slightly behind mesal Scute with segmentation delineated by small tubercle length 0.26 mm; eye tubercle width 0.35 following species: Archoleptoneta schusteri extreme of posterior margin of fourth coxae. tubercles, area behind eye tubercle tuberculate. mm; operculum length 0.30 mm; operculum Gertsch, Liocranoides sp., Trogloneta para­ First coxae with two prominent spinose tuber­ Eye tubercle obliquely truncate, declining pos­ width 0.32 mm. doxa Gertsch, and Usofila (Telema) sp. Of the cles. Anal plate smooth. teriorly; entire surface tuberculate. Eyes with Palp: trochanter 0.23 mm, femur 0.63 mm, other cavernicoles encountered, the most inter­ Palpal femur with five prominent proximal small corneas and no retinae. Tergites with sub­ patella 0.39 mm, tibia 0.53 mm, tarsus 0.39 mm. esting were specimens of Prokoenenia sp. (Pal­ dorsal spines and two slightly smaller distal dor­ marginal row of tubercles. Second endites se­ Leg 11: trochanter 0.16 mm, femur 1.14 mm, pigradida). sal spines; no setae or tubercles between dorsal tose, with acute ectal invagination behind mid­ patella 0.35 mm, tibia 0.96 mm, metatarsus 0.72 spines; ectal spur at base adjacent to second point. Labial processes large, rounded. Small mm, tarsus 1.14 mm. Banksula martinorum new species ventral spine. Proximal ventral spinose tubercle operculum with rounded anterior, margin adja­ Scute with segmentation delineated by tuber­ (Figure 3) on palpal tibia equal to ventral spinose tubercle cent to fourth coxae, posterior margin slightly cles, eye tubercle and area behind tuberculate. on patella. behind mesal extreme of posterior margin of Eye tubercle rounded, slightly conical, with HOLOTYPE.-Male. Body length 1.75 mm; Tarsal formula 4-6-5-6. fourth coxae. small corneas and without retinae. Tergites with scute length 1.49 mm; scute width 1.23 mm; eye Body concolorous pale yellow. Chelicerae setose, only slightly tuberculate. row of tubercles at margin. Second endites se­ tubercle length 0.26 mm; eye tubercle width 0.33 Penis typical of californica group. Palpal femur with four prominent proximal tose, mesally broad and rounded; labial pro­ mm; operculum length 0.18 mm; operculum ALLOTYPE.-Female. Similar to male. dorsal spines and three reduced distal dorsal cesses spatulate. Operculum large, extending width 0.19 mm. spines; no setae or tubercles between proximal posterior to hind coxae. Hind sternite and anal Palp: trochanter 0.19 mm, femur 0.88 mm, TVPE-SPECIMENS.-Holotype, allotype, 3 paratypes (I 1', 2 dorsal spines; ectal spur at base replaced by a plate with row of tubercles. All coxae tubercu­ patella 0.53 mm, tibia 0.65 mm, tarsus 0.42 mm. juv.): Heater Cave, 8 km N Columbia, Calaveras County, Cal­ broad, low tubercle; ventral margin straight. late. Leg 11: trochanter 0.21 mm, femur 1.81 mm, ifornia, 15 Mar. 1979, D. C. Rudolph, B. Martin, and S. Win­ Palpal tibia without significant proximal ventral Chelicerae with strongly tuberculate anterior terath. patella 0.39 mm, tibia 1.67 mm, metatarsus 1.23 spine. margin. mm, tarsus 2.37 mm. ETYMOLOGY.-This species is named for Tarsal formula 4-6-5-6. Palpal femur with six prominent proximal dor­ Scute with segmentation delineated by small arachnologist Barbara Martin and for Army Body concolorous light yellow. sal spines and four reduced distal dorsal spines; tubercles; eye tubercle and area behind slightly Corps of Engineers environmental planner Rob­ Penis typical of californica group, aedeagal no setae or tubercles between proximal dorsal tuberculate. Eye tubercle subconical, without ert Martin. velum held in smooth dorsal plate. spines; ectal spur well developed at base of 320 PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES, Vo!. 42, No. 11 BRIGGS AND UBICK: CAVE HARVESTMEN 321

FIGURE 4. Banksu/a grubbsi Briggs and Ubick, new species. Lateral view of body and left palpus of male holotype. FIGURE 5. Banksu/a elliotri Briggs and Ubick, new species. Lateral view of body and left palpus of male holotype.

proximal ventral spine, ventral suIface tuber­ 1977, A. Grubbs, N. Boice, and D. Broussard. Tuo/umne culate. County: Experimental Mine Cave, 3 km N Columbia, 25 Jun. dell; Lost Piton Cave, 6.5 km W Columbia, 6 May 1977, 26 to 16 C and the humidity from 82% to 97% (EI­ Tarsal formula 4-6-5-6. 1975, R. Lem; Mine tunnel along road to Experimental Mine, Mar. 1979, A. Grubbs, N. Boice, D. Broussard, S. Winterath, liott 1978). Specimens of Banksula melones and 2.5 km N Columbia, 25 Jun. 1975, T. Briggs (identification W. Ellioll, and J. Reddell; Bone Cave, 6 km w Columbia, 20 Body concolorous yellow-orange. only); Snell's Cave, 3 km N Columbia, 26 Feb. 1978, 14 Feb. Apr. 1980, T. Briggs and D. Ubick. Tuolumne County: Quarry B. grahami were found under rocks or wander­ Penis with folds at base of dorsal plate; apex 1978,2 Apr. 1979, S. Winterath, D. Rudolph, and J. Reddell; (McNamee's) Cave, 3 km NW Columbia, 24 May 1%9, G. ing on the floor or walls. They were rarely cap­ ofaedeagus enclosed in rounded sheath and held Crystal Palace Cave, 5 km N Columbia, 4 Nov. 1%7,21 Dec. Leung, W. Rauscher, and T. Briggs; Gate Pit Cave, 3 km NW tured in baited pitfall traps (Briggs 1975; Elliott within distal bifurcation of dorsal plate. 1977, 4 Feb. 1979, 25 Mar. 1979, T. Briggs, V. Lee, D. Ru­ Columbia, I Apr. 1979, D. Rudolph; Mine Cave, 3 km NW 1978). Although biased by more intensive winter ALLOTYPE.-Female. Similar to male. dolph, S. Winterath, A. Grubbs, W. Ellioll, B. Martin, and J. Columbia, I Apr. 1979, D. RudoJph, B. Martin, and S. Win­ collecting, records from McLean's and other Reddell; Porcupine Cave, 5 km N Columbia, 4 Feb. 1979, 28 terath; Scorpion Cave, 4.5 km N Columbia, 8 Feb. 1979, 25 Feb. 1979, D. Rudolph, S. Winterath, and B. Martin; mine on Mar. 1979, D. Rudolph, S. Winterath, D. Cowan, and T. caves suggest greatest activity in winter and TYPE-sPECIMENs.-Holotype, allotype, 4 paratypes (2 <5, I ridge, 4.5 km N Columbia, 22 Feb. 1979, D. Rudolph, S. Win­ Briggs; Vulture Cave, 4.5 km N Columbia, 10 Feb. 1979, 17 spring. 'i', 1 juv.): Pinnacle Point Cave, near Camp Nine Power terath, and B. Martin; Banksula Cave, 6 km N Columbia. 21 Feb. 1979, 22 Feb. 1979, 19 Mar. 1979, S. Winterath, D. Ru­ House, 9.6 km N Columbia, Tuolumne County, California, 8 At least 30 species of , most of Mar. 1979, D. Rudolpb, B. Martin, S. Winterath, and W. EI­ dolph, B. Martin, and W. Ellioll; McLean's Cave, 4.5 km N Feb. 1979, D. C. Rudolph, B. Martin, and S. Winterath. Para­ which were listed by Elliott (1978), coexist with lioll; McLean's Cave, 4.5 km N Columbia, 13 May 1967, 14 Columbia, 13 May 1967, 17 June 1967, 24 June 1%7, 14 Dec. types, 2 <5, 2 juv.: same locality, 20 Jan. 1978, W. Ellioll, A. Dec. 1977, 18 Dec. 1977,6 Mar. 1979, 27 Mar. 1979, 2 Apr. 1977, 18 Dec. 1977, 6 Mar. 1979, 27 Mar. 1979, K. Horn, T. Banksula melones and B. grahami in McLean's Grubbs, and S. Winterath. Paratypes, 20, I 'i': same locality, 1979, K. Hom, T. Briggs, W. EUioll, A. Grubbs, S. Winterath. Briggs, V. Lee, W. Elliott, A. Grubbs, S. Winterath, D. Ru­ Cave. Elliott (1978) identified some species, but I May 1977, A. Grubbs, N. Boice, M. McEachem and J. D. Rudolph, and B. Martin; Transplant Mine, 3 km N Colum­ dolph, and B. Martin; Transplant Mine, 3 km N Columbia, 17 many have not yet been identified. His feeding Davis. Paratypes, I 'i': Digger Pine Cave, 6.5 km N Columbia, bia, 17 Apr. 1979, D. Rudolph, S. Winterath, and E. vanlngen. Apr. 1979, D. Rudolph, S. Winterath, and E. vanlngen. Calaveras County, 22 Mar. 1979, D. Rudolph, B. Martin, S. experiments showed that captive Banksula, Winterath, W. Ellioll, and J. Reddell. Paratypes, 3 0, 5 ,,: NOTEs.-The migration of Banksula grahami NOTEs.-Some of the specimens collected in kept in McLean's Cave, will eat live Collembola Rabbit Hole Cave, 6.5 km N Columbia, Calaveras County, 22 into two of the mine tunnels recorded above is Vulture Cave and Bone Cave were found under but not equally abundant Psocoptera. Rudolph Mar. 1979, D. Rudolph, B. Martin, and S. Winterath. Para­ (1979) maintained eight immature Banksula in types, 1 (}, 1 'i': Grapevine Gulch Cave, 6.5 km N Columbia, the only known example of probable interstitial rocks in the twilight zone. All other collections Calaveras County, 22 Nov. 1979, D. Rudolph, B. Martin, and movement by a species of Banksula. were made in permanently dark regions of McLean's Cave using Collembola as food; three S. Winterath. Paratypes, I 0,4 'i': same locality, 27 Apr. caves. molted within 43 days. One adult and two im­ 1977, B. Hawson, A. Grubbs, J. Munthe, and M. McEachem. Banksula melones Briggs mature individuals maintained at the same time ECOLOGICAL REVIEW without food survived. ETYMOLOGY.-This species is named for Banksu/a me/ones BRIGGS 1974:8. Rudolph (1979) searched the mine tunnel into biospeleologist WiIliam R. Elliott. RECoRDs.--£'a/averas County: Cave of Skulls, 5 km NW Several ecological studies on Banksula (Briggs which Briggs and Elliott transplanted Banksula VARlATIONs.-Specimens taken in Pinnacle Columbia, 16 Apr. 1977.29 Mar. 1979, T. Briggs, D. Rudolph. 1975; Elliott 1978; Rudolph 1979) have been con­ me/ones, B. grahami, and miscellaneous arthro­ Point Cave are without retinae, although half of B. Martin, S. Winterath, W. Elliott, and J. Reddell; Quail ducted in McLean's Cave at the confluence of (Gerrill's) Cave, 5 km NW Columbia, 3 Jul. 1975, 17 Apr. pods from McLean's Cave. The transplanted the specimens taken in the remaining caves have the Middle Fork and the South Fork of the Stan­ 1977,30 Mar. 1979, W. Rauscher, D. Cowan, B. Martin, and population, which included a few hundred retinal pigment in their eyes. The specimen from S. Winterath; Barren Cave, 5 km NW Columbia, 30 Mar. 1979, islaus River (approximate elevation, 300 m). Banksula, appeared to be reproducing. The fu­ Digger Pine Cave has a relatively more conical D. Rudolph, B. Martin, S. Winterath, W. Ellioll, and J. Red­ This cave is one of the largest in the Calaveras ture of this transplant may depend on how well eye tubercle. Some specimens have only three dell; Beta Cave, 5 km NW Columbia, 7 May 1977, 29 Mar. limestone of the central Sierra Nevada and con­ 1979, A. Grubbs, D. Broussard, S. Winterath, D. Rudolph, tains the only sympatric populations of Bank­ conditions in the mine duplicate conditions in distal dorsal spines on the palpal femur. W. Ellioll, J. Reddell, and B. Martin; Poison Oak Cave, 5 km sula species. Banksula melones and B. grahami McLean's Cave. Ifthey both flourish, the trans­ NW Columbia, 29 Mar. 1979, D. Rudolph, B. Martin, S. Win­ planted Banksula species may demonstrate that BaoksuJa grahami Briggs terath, W. Ellioll, and J. Reddell; Coral Cave, 5 km N Colum­ are mixed in habitats near the base of a broad their sympatry in a small cave is stable. Banksu/a grahami BRIGGS 1974:7. bia, 24 Feb. 1978, 22 Mar. 1979, A. Grubbs, D. Rudolph, B. talus cone formed by debris gradually moving Martin, S. Winterath, W. Ellioll, and J. Reddell; Bryden's through two small entrances to the lowest levels RECORDs.--£'a/averas County: Moaning Cave, near Valle­ Cave, 5 km NW Columbia, 29 May 1977, A. Grubbs and B. of the cave. Because there is no flowing water BIOGEOGRAPHY citos, 22 Aug. 1%3, 22 Dec. 1%8, 6 Dec. 1977. R. Graham, Hopkins; Cone Cave, 5 km NW Columbia, 30 Mar. 1979, D. T. Briggs, W. Ellioll, A. Grubbs, and S. Winterath; Linda's Rudolph, B. Martin, S. Winterath, W. Ellioll, and J. Reddell; in the cave, the talus cone and deep-penetrating The distribution of Banksula species is similar Cave, 6 km w Columbia, 16 May 1977, A. Grubbs, N. Boice, Eagle View Cave No. 2, 5 km NW Columbia, 29 Mar. 1979, roots are important food sources for the inhab­ to the invertebrate troglobite distributions re­ and D. Broussard; Carlow's Cave, 6 km W Columbia, 16 May D. Rudolph, B. Martin, S. Winterath, W. ElIioll, and J. Red- itants. The cave temperature ranges from 14 C ported from caves in the Appalachian Mountains 322 PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES, Vo!. 42, No. 11

of the eastern United States in that these cave B. grahami occupy most of the available cav­ species tend to be bounded within "karst is­ erns. These populations seem to split into east­ lands," within which subterranean dispersal and ern and western clusters that do not correlate genetic communication readily occurs (Barr well with geology or water systems. The karst 1967; Culver et al. 1973). Such karst-island spe­ that contains the easternmost population of B. ciation exists for Banksula in the Sierra Nevada el/iotti is isolated by one kilometer of metavol­ if the limestone outcrops are widely separated. canic rock from the karst that contains the rest Thus, the species B. galilei Briggs, B. califor­ of B. elliotti and B. martinorum. Coyote Creek, nica (Banks), B. rudolphi new species, B. the much larger Stanislaus River, and the south grubbsi new species, and B. tuolumne Briggs fork of the Stanislaus that branches to the east occupy karst that is separated by many kilo­ have no apparent effect on the distribution of meters of nonporous rock (Fig. 1). The isolation species of Banksula. The four Stanislaus species of these cave species is, therefore, more com­ show increasing cavernicolous specialization in plete than that of the species in the Appalachian relative eye loss, from B. melones with the larg­ caves. The area of the karst in which B. galilei, est eyes, to B. elliotti with missing retinae, and B. californica, and B. rudolphi are found is B. martinorum with complete eye loss. One 0.02-0.1 km2 and is considerably smaller than might infer that adaptive radiation began with a the smallest karst island (to km2) studied in the B. me/ones-like ancestor and progressed to B. eastern United States (Culver et al. 1973). Fur­ el/iotti. If correct, one must explain how the in­ thermore, quarrying shows that these small out­ creasingly troglobitic species B. grahami and B. crops have small volume and little internal water elliotti were able to cross geologic and drainage flow. barriers. Further studies on the harvestmen of All known Banksula species are allopatric ex­ the Stanislaus River region are needed to explain cept for B. melones and B. grahami in Mc­ this unexpected distribution of species. It is re­ Lean's Cave. This suggests that sympatric grettable that this portion of the river will soon species compete, and the sympatry in McLean's be inundated by the New Melones Reservoir and Cave is a result of a recent invasion. About half some of the harvestmen caves will be lost. of the 70 or so Calaveras Formation caves care­ fully checked yielded a species of Banksula. LITERATURE CITED Thirty-one of these are located in the karst of BARR, T. c., JR. 1967. Observations on the ecology ofcaves. the Stanislaus River. Eighteen apparently hab­ Am. Nat. 101(922):475-491. itable caves in this region did not contain Bank­ BRlGGs, T. S. 1968. Phalangids of the laniatorid genus .'lira1­ cina (:). Proc. Calif. Acad. Sci. sula (Rudolph 1979). The absence of harvest­ 36(1):3-7. ment in caves located in karst outside of the --. 1971. Relict harvestmen from the Pacific Northwest. Stanislaus River region may be due to an uneven Pan-Pac. Entomo!. 47(3):168-169. distribution of their epigean ancestors. --. 1974. Phalangodidae from caves in the Sierra Nevada The distribution of the four species of Bank­ (California) with a redescription of the type genus. Occas. Pap. Calif. Acad. Sci. 108: 1-15. sula (B. melones, B. grahami, B. martinorum, --. 1975. Biological transplant project, New Melones and B. elliotti) that occupy the karst ofthe Stanis­ Lake, California-final report. Serial # DACW05-75-P-1845, laus region is not readily explained. Volcanic U.S. Army Corps of Eng., Sacramento Dist., Calif. rock divides Coyote Creek (west of the Stanis­ CULVER, D., J. R. HOLSINGER, AND R. BAROODY. 1973. To­ ward a predictive cave biogeography: the Greenbrier Valley laus River) from the Stanislaus River. It forms as a case study. Evolution 27(4):689-695. an irregular barrier between B. elliotti and B. ELLIorr, W. R. 1978. Final report on the New Melones cave melones, and separates B. me/ones from B. gra­ harvestman transplant. Contract #DACW05-78-C-0007, hami southeast of the Stanislaus River. Several U.S. Army Corps of Eng., Sacramento Dist., Calif. RUDOLPH, D. C. 1979. Final report on the status of the Me­ continuous bands of amphibolite divide the re­ lones cave harvestman in the Stanislaus River drainage. maining limestone regions into parallel lenses in Contract #14-16-0009-79-009, V.S. Fish Wild!. Serv., which allopatric populations of B. melones and Wash. D.C.

CALIFORNIA ACADEMY OF SCIENCES Golden Gate Park San Francisco, California 94118