Nigma is a genus of cribellatearaneomorph spiders in the family Dictynidae, and was first described by Pekka T. Lehtinen in 1967.[2] They have a wide distribution, including Eurasia, North America, and Northern Africa.[1]N. walckenaeri is one of the biggest members of the Dictynidae, growing up to 5 millimetres (0.20 in) long. They are translucent green and sometimes have red or black markings on the abdomen.[3]
^Lehtinen, P. T. (1967). "Classification of the cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha". Annales Zoologici Fennici. 4: 199–468.