He slighted the usual tourist sights in the “Idle Excursion,” but his notebook showed that he visited Devil’s Hole, the oldest attraction on the Islands. “Devil’s Hole,” his note read, “angel fish, blue & yellow.” The collapsed sea cavern, also known as Neptune’s Grotto or Groupers’ Grotto, had been a commercial operation since the 1830s. Situated by Harrington Sound, in Smith’s Parish, it was fed instead by a narrow passage to the ocean. The Royal Gazette described Devil’s Hole as “an enchanting walled fish-pond,” and the Bermuda Pocket Almanack promised that “you will see a few of the beautiful Angelfish . . . gliding timidly between the great unsightly groupers.” Lady Brassey said the groupers were “fierce, voracious creatures,” and Julia Dorr wrote of their “great sluggish bodies and horribly human faces.” Harper’s Monthly reported in 1874 that Devil’s Hole was usually stocked with one thousand fish, “though it will hold twice as many.” By 1883, the New York Times correspondent could see only fourteen groupers, one angelfish, two turtles, and a solitary fish he could not identify. A few years later, Howells found many more:

In this deep pool, sunken in the rock, live several hundred groupers, a fish with no more distinction than a cod, crowded together, and apparently always hungry. They have big heads and enormous mouths, which are blood-red inside, and when they are packed together, standing on their tails, with open mouths lifted out of the water in expectation of the bread which is thrown to them, they present in their ravenous obtrusiveness as disgusting a sight as can anywhere be seen. We had an impression that this must be the Washington of the islands, where all the politicians were standing on their tails with their mouths wide open. This is enough to say about the groupers.

Howells, too, was impressed by the beauty of the Bermuda angelfish (Holacanthus bermudensis), which he accurately described as “flat and oval in form, of a cerulean blue, with two long streamers edged with yellow.” He pronounced it “apparently one of the happiest, as he is one of the most graceful, of all marine inhabitants”. Clemens, however, saw the angelfish as female. An obscure notebook entry—“The Admiral’s secretary & the angel fish”—defies explication, but in later years he made friends with schoolgirls and referred to them as the angelfish of his aquarium.