Pholcus Walckenaer 1805
Creators: name: Zhang, Feng
name: Zhu, Ming-Sheng
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Pholcus

description: Pholcus Walckenaer, 1805   
 Pholcus Walckenaer 1805: 80. Simon 1893: 470–471. Huber 2000: 77. Huber 2001: 108–111. Hu 2001: 81.   
 Type species: Aranea phalangioides Fuesslin, 1775, by subsequent designation.   
 Diagnosis. The most useful characters in distinguishing Pholcus from other genera in the family Pholcidae are the male genital structures, especially three projections of the tarsus bulb, traditionally called the uncus, the appendix and the embolus. The uncus is usually large, rather flat, heavily sclerotized, and is provided with many teeth or scales. The appendix is smaller (even absent in some species), usually hook-shaped, also sclerotized, and is either a single rod or split into two or even three parts. The embolus lies between the uncus and appendix, is soft and transparent, and is thus easy to overlook (Huber 2001). Other characters are the conservative male chelicerae (with various apophyses), the shape of the procursus (usually with ventral boss and complicated tip), and in the female, the knob-, necktie-, whip- or worm-shaped apophysis on the often roughly triangular, rectangular or oval epigynum.   
 Description (refers to Chinese species of Pholcus only). Medium to large-sized pholcids, the body frequently being 4 to 10 mm in length. They generally have flat, plate-shaped cephalothoraces (Figs. 17C and 30C), pale ochre with distinctive brown marks of three general patterns in China: the first pattern (Figs. 15C, 20C, 23C, 25C, 32C, 37C, 41C or 52C) we named ‘Peking-opera-mask’ type, most species belong to it; the second (Figs. 3C, 4A, 14D, 21D, 26C, 36C or 46C) we named ‘butterfly’ type, some species belong to it; the third (Figs. 28A or 10D) we named ‘stripe’ type, only two species are in this group. Carapace with black median line but no thoracic furrow. Clypeus generally pale ochre, with or without marks, high and without sexual modifications. The eye region is light brown, more or less elevated (Figs. 40A and 43A); most species have eight eyes in three groups, two median AMEs as a group and others in two lateral triads; most lateral triads not on eye-stalks, sometimes male triads on short (Figs. 27C and 32C) or longer eye-stalks (Figs. 39A–B). A few species have six eyes, such as P. elongatus redescribed below (Fig. 10D). Chelicerae fused at base, with lamina opposing cheliceral fang. In females normal, male chelicerae are frequently equipped with two or three pairs of special apophyses, often species-specific in morphology: the first pair, dark distal apophyses with two small modified hairs on each (Figs. 18D–E, 57E–F), a second pair of light apophyses proximolaterally (Figs. 23E, 29E and 32E), and finally, a pair of unsclerotized apophyses proximocentrally which may be very small (Figs. 33E and 35E), or even absent in some species (Figs. 27D and 29E). Sternum pale ochre, about as wide as or wider than long, with varying brown patterns, some species with three or four pairs of submarginal pale patches and central pale patch (Figs. 45F and 52F), some species have no markings (Fig. 21F), some species with only median markings (Figs. 17F and 33F), others with irregular or regular spots (Figs. 11F, 24F and 29F). Labium and endites generally light brown and unmodified.   
 Pedipalps are unmodified in females (Fig. 38A), but conspicuously large and strong in males (Figs. 29H–I and 42H–I). Their complex morphology has been well documented by Uhl et al. (1995). The male palps are generally described as below. Coxa unmodified. Trochanter generally with a ventral apophysis which is long or short in different species (Figs. 29H and 27H); some species with a retrolateral apophysis provided distally with a strong modified hair (Fig. 38D). Femur large, with a ventral bulge which corresponds to a depression on the procursus (Figs. 16I, 20I and 26I), and sometimes with a dorsal projection retrolaterally (Figs. 3G, 26I and 42I). Patella generally triangular in retrolateral view, and unmodified (Figs. 17I, 20I and 24H). Tibia swollen, robust, spindle-shaped (Figs. 3F, 24H and 32H), bears two trichobothria laterally and dorsally (Figs. 35H, 41H and 47G); sometimes with an ear-shaped tubercle prolaterally (Figs. 11H, 35H and 37H) or a triangular projection ventrally (Figs. 15H, 43I and 46H). The tarsus consists of two parts: a proximal part carrying several bristles, a capsulate tarsal organ and the genital bulb (Figs. 47F, 59C and 63I), and a distal part (also called the procursus), a massive organ with many heavily sclerotized structures. The tip of the procursus is very complex in structure and has important diagnostic characters. The bulb is a whitish globular part with three projections, which are traditionally called uncus, appendix and embolus (Figs. 5I, 52H and 36H); the uncus is usually large, rather flat, heavily sclerotized, and is provided with many teeth or scales (Figs. 7I, 54F and 56H); the appendix is smaller (even absent in some species, as in Figs. 6G, 19E, 48I and 64H), usually hook-shaped and sclerotized, and is either a single rod or split into two or even three parts (Figs. 52H, 61H, 60H and 27F); the embolus lies between the uncus and appendix, is soft and transparent (Figs. 23H, 34F and 46H).   
 The legs are exceedingly long and slender, often characteristically annulated, femora with dark and pale apical rings, patellae entirely dark, tibiae with a dark proximal ring and dark and pale apical rings (Saaristo 2001); with numerous hairs on legs, but apparently without spines, curved or vertical hairs; tarsi with several pseudosegmentations and capsulate tarsal organs (Figs. 7B, 18B, 22E and 34G). Male gonopore with four or five (few species) epiandrous spigots (Figs. 7C, 18C, 22C and 34H). Chinese species of Pholcus generally have elongate or globose abdomens, even both types of abdomen occurring in conspecific specimens; a few species with worm-shaped abdomens (Figs. 39A and 10E). Abdomen mostly grey, dorsally and laterally with distinctive blackish marks or spots (Figs. 15C, 2C and 32C), but a few species without any dark spots (Figs. 10E and 56C). The male genital area with or without small brown marks, ventrally with long central brown lines or stripes posteriorly in some species, but others without dark patterns. The female genitalia are usually relatively simple externally, comprising a more or less elevated area divided by a simple slit into anterior and posterior plates (Figs. 11A, 16A, 34A and 53A); there may be special outgrowths (variably sclerotized apophyses, e.g. knob-, whip-, worm-, hook-, necktie-shaped in Figs. 54A, 25A, 16A and 46A, also called a ‘scape’ in some references) and pits on the anterior plate (also called ‘genital plate’), the posterior plate is also called ‘accessory plate’ (Saaristo 2001). However, the internal morphology is very complicated (Huber 1995; Uhl 1994) generally with a sclerotized arch anteriorly and a pair of pore plates posteriorly (Figs. 5B, 9B, 14B, 21B and 26B).   
 The spiders of Pholcus have six spinnerets in three rows (Figs. 18I, 44F, 50G and 57G), anterior lateral spinnerets (ALS) each with one widened major ampullate gland spigot, one pointed conical spigot, and six piriform gland spigots (Figs. 18J, 22H, 34B, 44G and 57H); posterior median spinnerets (PMS) with two spigots each (Figs. 18K, 22I, 44H, 57I and 59I), one aciniform gland spigot, the other ampullate gland spigot; and the posterior lateral spinnerets (PLS) without any spigots (Figs. 18L and 44I).   
 Remarks. See Huber 2001.
description: Published as part of Zhang, Feng & Zhu, Ming-Sheng, 2009, A review of the genus Pholcus (Araneae: Pholcidae) from China, pp. 1-114 in Zootaxa 2037 (1) on pages 6-8, DOI: 10.11646/zootaxa.2235.1.2, http://zenodo.org/record/5317608