Designed by Edward Reed, the Royal Navy Director of Naval Construction, they were equipped with a ram bow. The hull was of wooden construction, but they were the first class of sloops to incorporate a form of composite construction; they had iron cross beams while retaining wooden framing.
Propulsion was provided by a two-cylinder horizontal single-expansion steam engine by Ravenhill, Salkeld & Company driving a single 15feet screw. Vestal and Nymphe were fitted with three-cylinder Maudslay engines.
All the ships of the class were built with a barque rig.
The class was designed with two 7-inch (6½-ton) muzzle-loading rifled guns mounted on slides on centre-line pivots, and two 64-pounder muzzle-loading rifled guns on broadside trucks. Dryad, Nymphe and Vestal were rearmed in the early 1870s with an armament of nine 64-pounder muzzle-loading rifled guns, four each side and a centre-line pivot mount at the bow.
| Name | Ship Builder | Launched | Fate | |
|---|---|---|---|---|
| Pembroke Dockyard | 1865 | Sunk in collision with SS Osprey, off Start Point, English Channel 10 July 1866 | ||
| Pembroke Dockyard | 1865 | Sold to Castle for breaking in December 1884 | ||
| Devonport Dockyard | 1866 | Wrecked off Cape Blanc on Miquelon Island, off the Atlantic Coast of Newfoundland and Labrador 21 May 1874 | ||
| Devonport Dockyard | 1866 | Sold in September 1885 and broken up in April 1886 | ||
| Pembroke Dockyard | 1866 | Sold for breaking on 7 November 1882 | ||
| Devonport Dockyard | 1866 | Sold for breaking in December 1884 |