This issue is dedicated to Dr. Christo Deltshev, the doyen of Bulgarian araneology. It contains seventeen arachnological publications, including a concise biography of Dr. Deltshev, a list of his scientific publications and his described taxa. The volume comprises taxonomic contributions in the spider families Hypochilidae, Sicariidae, Dysderidae, Hersiliidae, Theridiidae, Linyphiidae, Lycosidae, Dictynidae, Gnaphosidae, Sparassidae, Philodromidae and Salticidae and fossil taxa in the harvestmen suborders Dyspnoi and Eupnoi, written by a total of 36 authors. Four new genera and 37 new spider and harvestmen species have been described in this volume, and dozens of new taxonomic alterations (new combinations, new synonyms, new statuses, etc.) are proposed too. Geographically, the papers deal with material originating from Europe, Africa, Asia, North and South America. There is also an overview of the use of barcoding to identify spiders in species-rich genera.