Hypsibius pallidus Thulin 1911

Hypsibius pallidus shows quadrangular or granular-shaped macroplacoids, as a difference from Hypsibius convergens and H. dujardini, which have rod-shaped macroplacoids. In addition, this species has doubleclaws similar to those present in Ramazzottius oberhaeuseri . Mean body size, among the 14 individuals collected, was 534 μm (SD 147), range 308 to 803 μm. The species is considered cosmopolitan (McInnes 1994). In the Iberian Peninsula, it has been recorded for Spain (Rodríguez Roda 1946, 1952; Maucci & Durante Pasa 1984; Lewin Osorio 1984) and Portugal (Da Cunha 1941, 1944a, 1947b; Fontoura 1981). This is the first time it is recorded for Madrid Province (Table 2). Hypsibius pallidus was found at 7 sampling points (Table 3) from LF and MR samples.