Figure 34 from: Bousquet Y (2012) Catalogue of Geadephaga (Coleoptera: Adephaga) of America, north of Mexico. ZooKeys 245: 1-1722. https://doi.org/10.3897/zookeys.245.3416

Figure 34 - Trichotichnus dichrous (Dejean). This eastern species is color-dimorphic, a phenomenon rarely seen in North American carabids. While most adults have the head and pronotum reddish-yellow and the elytra much darker, a small number of adults are known to be uniformly piceous. When he described the species, Dejean had a single specimen of the common morph. The strong color contrast between the forebody and elytra prompt him to propose the name dichrous, from the Greek prefix di- (two) and chroma (color of the skin).