rastus

Perry Belmont's wife is the former Miss Jessie Ann Robbins and had been married to Henry T. Sloane before her marriage to Belmont in April 1889. See NYT query.nytimes.com/gst/abstract.html?res=F40614FC3E5811738... Vernon and Irene Castle were best known for their dancing, but Vernon Castle was also a polo fan. See The [Chicago] day book., May 29, 1915, NOON EDITION, Image 11 chroniclingamerica.loc.gov/lccn/sn83045487/1915-05-29/ed-...

Looks like she's holding her pet monkey, as she does in the next shot in the series:

Thanks so much for your research swanq. And yes, artolog, it appears as if the other photograph of Irene Castle was taken at this event given her dress and the way she is holding her pet monkey. We'll fill in the names in the caption the next time we update the record.

Irene Foote Castle (1893-1969), dancer: en.wikipedia.org/wiki/Vernon_and_Irene_Castle Showing off her no-corset style, her bobbed hair, and her pet monkey (is he smoking, or is that a scratch on the plate?).

Even at the largest size it looks like the monkey is smoking, or otherwise has something in it's mouth.

I'm going with cigarette.

According to The Toronto World - Mar 26, 1916 news.google.com/newspapers?nid=22&dat=19160326&id... Irene Castle had a pet French Guinea monkey called Rastus, "much photographed and written of." Apparently when she sat down to write to her husband, the monkey insisted on having paper and pencil!

Thanks to pennylrichardsca and swanq for your research into this fascinating woman. And that is most likely "Rastus" whom she's holding. But I can't verify whether or not she let him smoke. We'll add some of this information to the record the next time we update.