Tetrablemmidae, a spider family newly recorded from Cambodia (Arachnida, Araneae)

Abstract The family Tetrablemmidae O. Pickard-Cambridge, 1873 is reported from Cambodia for the first time. Two species belonging to the genus Tetrablemma O. Pickard-Cambridge, 1873 are documented as new to science: Tetrablemmakepensesp. n. (male, female) from Kep Province and Tetrablemmasokensesp. n. (male, female) from Battambang Province. Diagnoses, morphological descriptions, and comparative illustrations are provided.

Several specimens of armored spiders found in a cave and the leaf litter in Cambodia were examined, belonging to two species. Here they are described as Tetrablemma kepense sp. n. and T. sokense sp. n. Both species represent the first report of the family Tetrablemmidae from Cambodia.

Materials and methods
All type specimens were acquired by manual collection and preserved in 75% denatured ethanol solution, and are deposited in the Senckenberg Research Institute, Frankfurt, Germany (SMF) and the Natural History Museum of the Sichuan University in Chengdu, China (NHMSU).
Specimens were examined and measured under an Olympus SZX7 stereomicroscope. Further details were studied under an Olympus BX43 compound microscope. Male palp and female genitalia were examined and photographed after they were dissected and detached from the spiders' bodies. To reveal the configuration of spermathecae and the course of the spermophor in the palpal bulb, they were treated in lactic acid and embedded in Hoyer's solution before taking photos. Photographs were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels) mounted on an Olympus BX43 compound microscope. Images were combined using Helicon Focus 3.10 software (Khmelik et al. 2006).
All measurements in the text or figures are given in millimeters. Leg measurements are provided as following: total length (femur, patella, tibia, metatarsus, and tarsus  Lehtinen 1981).
Note. The gender of Tetrablemma is neuter, therefore two species names described previously are amended (see below). The ending "-ensis" denotes a place, a locality or a country. It forms an adjective with two endings: "-ensis" for genera masculine or feminine in gender, and "-ense" for genera neuter in gender.
Palp ( Figure 4A-C): femoral cuticle ventrally granulated, approx. 2.2 × longer than patella; patella short and smooth, distinctly longer than cymbium; tibia wide, swollen, approx. 1.2 x wider than femur, with a distal-dorsally trichobothrium; cymbium short, constricted, bearing sparse long setae; bulb long pear-shaped, surface of dilated area smooth, surface of sub-distal area rugose; embolus strongly sclerotized, starting from the apex of bulb; embolic tip cuneate, twisted, sharply pointed; spermophor coiled into a loop in bulb, abruptly twisting to narrow, and open at the embolic tip.
Prosoma (Figs 3C-D, F, H, 5): coloration and modification as in male, but instead cheliceral horns a small nodule fronto-proximally. Clypeus lower than in male, palps distinctly reduced, palpal tibia with a dorsal trichobothrium. Legs as in male. Opisthosoma: dorsal and ventral scuta as in male; lateral scutum I long, extending beyond posterior margin of preanal scutum; postgenital scutum long, straight, bearing a row of long setae, mesally wide, laterally narrow; preanal scutum weakly sculptured, wider than long, nearly rectangular, with sparse stiff setae.
Habitat and biology. Cave. The cave entrance was ca. 80 altitudinal meters above the ground at an isolated limestone hill. Almost under every stone only one spider   was found; silken strands used by the spiders may be the reason for this territoriality ( Figure 5). It was the highest density of Tetrablemmidae observed in a cave by the last author. Besides Tetrablemmidae, there were Oonopidae (also found under stones), Pholcidae, Sparassidae, Uloboridae, Hersiliidae, Agelenidae, Amblypygi and Isopoda.
Distribution. Known only from the type locality ( Figure 6).