126 2006. The Journal of Arachnology 34:126–134 THREE NEW SPECIES OF PHOLCUS (ARANEAE, PHOLCIDAE) FROM THE CANARY ISLANDS WITH NOTES ON THE GENUS PHOLCUS IN THE ARCHIPELAGO Dimitar Dimitrov 1 and Carles Ribera: Departament de Biologia Animal, Universitat de Barcelona, Av. Diagonal, 645, Barcelona-08028, Spain. E-mail: ddimitrov@ub.edu ABSTRACT. Over the last decade, numerous papers focusing on the fauna of the Canary Islands have reported that many spectacular species radiations have taken place, leading to a very high level of ende- micity in this archipelago. The species of the genus Pholcus are a very good example of such a fascinating process. The Canary Islands harbor the highest number of endemic species of this genus. Therefore, in order to obtain a detailed picture of the diversity and the phylogeny of the Canarian Pholcus, a complete taxonomic revision is required. The present work is the second contribution to achieve this goal. Three new species of Pholcus are described: Pholcus bimbache, P. anachoreta and P. corniger. The first endemic species of Pholcus from El Hierro (P. bimbache) is reported; P. anachoreta is the only Pholcus species found on the Montan ˜a Clara Islet; and P. corniger is the second and most troglomorphic species known from Tenerife. Keywords: Araneae, Pholcidae, Pholcus new species, taxonomy, Canary Islands The Canary Islands are situated about 100 km off the northwestern coast of Africa. This volcanic archipelago was formed during var- ious volcanic episodes and is nowadays com- posed of seven main islands and several islets. All of them are situated almost on a straight line with an east-west orientation, with the age of the islands decreasing towards the east. The estimated ages of the islands are: Fuerteven- tura 20–22 My, Lanzarote 15–19 My, Gran Canaria 14–16 My, Tenerife 11.6–14 My, La Gomera 10–12 My, La Palma 1.6–2 My and El Hierro 0.8–1 My (Anguita & Herna ´n 1975; Ancochea et al. 1990; Coello et al. 1992). The older islands, Fuerteventura and Lan- zarote, are lower in elevation due to the ef- fects of erosion. As a result of their low height they receive less moisture from the northeast trade winds than the other, higher islands. This, and the proximity of the Sahara Desert, renders them the driest islands in the archi- pelago, with most of their habitats being dry lowlands. The remainder of the Canary Is- lands have higher mountains, reaching an el- evation of 3717 m (Teide, Tenerife). This high 1 Current address: George Washington University, Department of Biological Sciences, 2023 G. Street, NW, Washington, DC, 20052. E-mail: dimitard@ gww.edu elevation combined with the trade winds (hu- mid from the northeast and dry from the northwest), causes a thermic inversion that forms a cloud belt between 600 and 1000 m. These clouds are almost permanent on the northern slopes, favoring the growth of a char- acteristic subtropical forest named laurel for- est. Differences in humidity and elevation be- tween and within islands are the main reasons for the development of a large variety of hab- itats. The so-called hypogean environment also contributes to changes in the diversity of habitats. In the case of the Canaries it is formed by lava tubes and the MSS (mesocav- ernous shallow stratum) (Oromı ´ et al. 1986; Medina 1991). This high diversity of ecolog- ical niches and the initial emptiness of habitats provide the best conditions for species radia- tions. The spider genus Pholcus Walckenaer 1805 is a good example of this process. The 114 species that it comprises are distributed almost all around the world. However, it is interesting to note that there are no indigenous Pholcus species in Central and South America and only a few are known from North America. Before the present study, eighteen species of Pholcus had been reported from the Canary