Clementis
Sonata | A 4. 2 Violin, Viol di Gamba e Violone | Clementis
D-W, Cod. Guelf. 34.7 Aug.2° (Jakob Ludwig Partitur Buch), pp. 170-172, n° 84
The term Violone certainly means an 8-foot instrument of the violin family.
The attribution to Clemens Thieme (1631-1668) has been proposed.
Michael Fuerst, The Partiturbuch Ludwig: An Introduction and Thematic Catalogue, «The Viola da Gamba Society Journal», 4 (2010), pp. 74-102. http://vdgs.org.uk/journal/Vol-04.pdf