Blackwall is a surname. Notable people with the surname include:

Life history of Oedothorax fuscus (Blackwall, 1834) (Araneae, Linyphiidae) in a heavily grazed pasture
Contact Metamorphism of Serpentinite, Chloritic Blackwall and Rodingite at Paddy-Go-Easy Pass, Central Cascades, Washington
The Erigonine Spiders of North America. Part 6. The Genus Walckenaeria Blackwall (Araneae, Linyphiidae)
Exposure of the ground dwelling spider Oedothorax apicatus (Blackwall) (Erigonidae) to spray and residues of deltamethrin
Is the Hairy Groove in the Gibbosus Male Morph of Oedothorax Gibbosus (Blackwall 1841) a Nuptial Feeding Device?
Laboratory observations on the development and reproduction of Erigone atra Blackwall, 1833 (Araneae, Linyphiidae).
CHROMOSOMES OF CROSSOPRIZA LYONI (BLACKWALL 1867), INTRAINDIVIDUAL NUMERICAL CHROMOSOME VARIATION IN PHYSOCYCLUS GLOBOSUS (TACZANOWS...
Effects of Prey Abundance on the Development of the Spider Agelenopsis potteri (Blackwall) (Araneae: Agelenidae)
Reproduction and survival of linyphiid spiders, with special reference to Lepthyphantes tenuis (Blackwall)
Sown weed strips in cereal fields: overwintering site and “source” habitat for Oedothorax apicatus (Blackwall) and Erigone atra (B...