Sub-subseries consists of visual and some textual information concerning particular neurological cases. This material was sent to Dr. Penfield by other neurologists. (E/VS = Events / Visual Sent)

Sub-subseries consists of Dr. Penfield's collection of glass lantern research slides.

Sub-sub-series consists of active office files, filed by subject, related to Dr. Penfield's writings and travels. (C/SW = Correspondence/Subjects Writing)

The Comic Valentines sub-subseries contains 55 cards printed on cheap paper and are typically hand-coloured. The Comic Valentines sub-subseries consists of single-page greeting cards with woodcut images representing several stereotypes, usually poking fun at someone’s profession or appearance. They typically contain a woodcut caricature of the recipient and a short and usually offensive poem. Comic valentines, sometimes referred to insult valentines or vinegar valentines, were given to either poke fun at a friend or to offend someone who was very disliked. People who received these types of cards rarely kept them, therefore all the comic valentines featured in this series are blank and like stationer’s stock.

The Handmade Valentines sub-subseries is comprised of 131 cards using a variety of craft materials.The Handmade Valentines sub-subseries consists of cards that have been collaged together by someone and include hand-finished details. They are typically made with a melange of lace-paper, embossed paper, cut-out pictures and paper shapes. They might be finished with a hand-written or printed message and might be hand-drawn or at least assembled by hand. The materials used in these handmade valentines are diverse and can include metal trinkets, ribbon, satin, fabrics, artificial or dried flowers, beads, feathers and wire.

The Manufactured Cards sub-subseries 33 consists of Valentines that have been cut and printed by machine. They are typically a single-fold card or may be printed on a single piece of cardstock. These cards have no evidence of human manipulation in its manufacturing and are typically one-dimensional.

The Ephemera sub-subseries consists of miscellaneous, non-greeting card items, composed of 5 printed documents and 1 physical object. In it are writers, small pamphlets destined to provide the reader with tips on how to write letters and messages to all sorts of people, as well as greeting card catalogs and press. There is also a wall pocket, presumably used to hold cards, that was equally being sold by wholesalers of greeting cards.

The Miscellaneous Greeting Cards sub-subseries contains all cards that are not Valentines. They were either found within the same seller’s scrapbooks as the Valentine cards or were found mixed with the fonds, possibly belonging to a same recipient as the some of the Valentine cards. The other greeting cards take various forms and shapes and typically commemorate an important life event.

The Rebus Valentines sub-subseries consists of printed valentines that contain puzzles or cryptographic messages that the recipient must decipher. This can include messages written in hieroglyphics or hidden in endless knots.

The Scrapbooks sub-subseries contains a full scrapbook of publisher’s samples, as well as individual scrapbook pages with multiple attached cards that have been extracted from a book. The cards in these scrapbook pages usually include a bulk price per dozen and instructions from the publishers, such as to specify the desired message inside the card. There are some pages that may be from a personal scrapbook as the cards pasted inside it are signed by a sender.