(Not a costume of Van Dyke himself, but meant to represent the style of the dresses worn in his paintings, this is one of those hilarious reimaginings of a historical era with the general style worn over completely inappropriate Victorian underpinnings for a very peculiar silhouette.)
Full plain skirt; muslin apron, edged with pointed lace; bodice with revers; sleeves to wrist; hair in curls.
Source: Holt, Ardern. Fancy Dresses Described, 5th Edition. London: Debenham & Freebody, 1887.