M. Faura i Sans, in his Recull espeleològic de Catalunya (1909), mentions a cavity under the name avenc de la Sal de Llop, attributes to it a depth of 34 metres and explored in 1908. It was certainly one more of the many cavities that the woodcutter Cells de Vallirana had shown him. In 1936, during the campaigns of the Club Muntanyenc Barcelonès in the area of l'Ordal, directed by N. Llopis Lladó, they were informed that during the work of extracting “sparry calcite” at the bottom of a fissure the passage towards a new pit had been discovered. The people of the CMB set about exploring the new pit, named dels Esquirols. The explorations continued until February 1937 (in the middle of the war) and, according to the authors, they attribute to it a partial depth of between 120 and 180 metres. The explorations were not resumed until 1 and 2 April 1950 by members of the GES of the CMB, who set the maximum depth level at – 202 metres. Visits in search of new routes became continuous from the beginning of 1951, led by Jordi Montesinos. Unfortunately, on 20 May of that year, the hemp rope on which he was making the rappel of the entrance pit broke, causing the fall and death of the young speleologist of the GES (it was the first fatal accident in Catalan speleology). In the same 1951, his companions finished the exploration of the lateral route that bears his name. The cavity became a classic and for many years was assiduously visited by generations of Catalan speleologists. There is always doubt about the correct depth, since the level – 202 seems exaggerated. In 1970, a survey by the SIE-CEA set the maximum depth at – 178 and a new survey by the GES in 1975 corroborates this same level. In 1979, members of the CE de Cervelló, while reviewing unknowns, found some new lateral pits in the intermediate zone of the cavity. Almost at the bottom, they passed an extremely narrow crawl and located two small drops that set the new maximum depth level at – 184. On the GES survey (1975) they made the appropriate corrections, publishing the most up-to-date survey so far. In 1980, Joan Borràs (GES) wrote a note about the cavities mentioned by Faura in the area of the Lledoner and the great confusion that exists about it. He reaches the conclusion (more by intuition and/or elimination than by concrete documentary data) that the avenc de la Sal de Llop was none other than what since 1936 has been known as avenc dels Esquirols. Recently (2010) and through the documentary research of Mr. Enric Aragonès, we have been able to learn that in reality it was Father Marcet who really and on his own initiative explored some pits in the area of l'Ordal and one of them was the avenc de la Sal de Llop, later communicating the results by letter to M. Faura. In this document, dated 12-9-1908, he clearly explains that once down the first pit, he penetrated through a hole of 60 x 30 cm and reached a high chamber (Sala de l'Orgue). This shows that the information received by the members of the CMB in 1936 was not correct and that the continuation of the first pit of the avenc dels Esquirols was already known 28 years earlier.

Troglocharinus Ferreri Reitt.

• 3 specimens collected by F. Español on 27-1-1927
• 9 specimens collected by O. Escolà on 3-3-1962
• 8 specimens collected by O. Escolà on 21-10-1962
• 14 specimens collected by Ll. Auroux on 31-1-1965
• 13 specimens collected by Seijas on 8-8-1965