Trapdoor spiders (Bothriocyrtum californicum) from nine southern California sites, including three on Santa Catalina and Santa Cruz Islands, were compared, based on variation at nine allozyme loci. Populations were generally in Hardy-Weinberg equilibrium, with no evidence of inbreeding. Levels of genetic variability in the six mainland populations were relatively high (mean H_o = 10.8%, mean P = 42.6%), while it was reduced (H_o < 2.0%, P < 23.0%) in two of three island populations, consistent with the loss of variability usually associated with island colonization. Genotype frequency distributions indicated a recent reduction in effective population size for spiders from Webb School of California, perhaps a consequence of habitat destruction associated with school construction in 1920–1930. Interpopulation differentiation was generally substantial and did not bear a simple relationship to physical distance. These findings suggest that, while B. californicum populations generally possess ample levels of genetic variability relative to other invertebrates, bottlenecks do occur, and populations are usually genetically isolated. To foster preservation of the existing gene pool, management of B. californicum should focus on maintaining as many populations in situ as possible and facilitating connections between them, while also creating or restoring habitat for potential colonization.

An annotated catalogue of Albanian arachnids held in the Museum für Naturkunde (MfN) Berlin is presented, including the type of the spider Zoropsis oertzeni Dahl, 1901. Most of the material was collected from the coastal city of Vlora in c. 1887 by the German naturalist Eberhard von Oertzen (1856–1909). This makes it one of the oldest arachnological collections from Albania. Biographical notes on von Oertzen are also included. Most of the MfN species have previously been recorded for Albania, but we provide here a new record of Sitticus rupicola (C. L. Koch, 1837) as well as locality data and collection numbers for all MfN voucher specimens. Of particular interest is the re-identification of two spiders as Dysdera corfuensis Deeleman-Reinhold, 1988; including the first record of the female from Albania. The bat tick Ixodes vespertilionis C. L. Koch, 1844 is labelled as Albanian, and would be a new record for the country but the locality is more likely to be in modernday Serbia.

The type specimens of the two pseudoscorpion species described by di Caporiacco (1947) from Guyana (former British Guyana) are studied in detail. Geogarypus incertus di Caporiacco, 1947 is considered a valid species and its type locality is clarified as Guyana, Upper Demerara—Berbice region, upper Demerara valley, near Kurupukari. Paratemnus guianensis di Caporiacco, 1947 is considered ajunior subjective synonym of Paratemnoides nidificator (Balzan, 1888) (syn. nov.). Lectotypes are designated for Paratemnoides minor (Balzan, 1892) and Paratemnoides nidificator. Geogarypus incertus and Paratemnoides nidificator are new additions to the fauna of French Guiana.

A trigonotarbid arachnid referable to Anthracomartus voelkelianus Karsch, 1882 is described from the Late Carboniferous (Moscovian) (= Westphalian C) of Jerusalemsberg near Dobšiná in eastern Slovakia. This record is significant as both the first fossil arachnid formally described from Slovakia and, whilst it does not come from a classic Coal Measures locality with a terrestrial palaeoenvironment, the sediments were deposited in a marine—deltaic environment typical for arachnid fossils. An overview of the distribution of the 17 currently recognized species of Anthracomartidae is presented.

Fragments of a fossil scorpion collected from Silurian (Ludfordian, c. 420 Ma) strata near Trecastle in Powys, Wales, are described. They represent one of the oldest records of Scorpiones, of which only five other species are known from the Silurian. Given the incomplete nature of the new material, which includes a largely complete carapace with anteriorly positioned median eyes, we cannot assign it to any particular family or genus. However, the pustulate carapace ornament and preserved pattern of sulci are reminiscent of certain, much larger, fossil scorpions such as the Devonian Praearcturus gigas Woodward, 1871 and the Carboniferous Gigantoscorpio willsi Størmer, 1963.