Symmetroscyphus intermedius (Congdon, 1907)

(fig. 7C–D)

Thyroscyphus intermedius Congdon, 1907: 482, figs 33–36.

Symmetroscyphus intermedius — Calder, 1986: 380, figs 1–4.— Calder, 1991d: 77, figs 39–40.

Material examined. Stn. 1: 25.01.2008 —a small, sterile colony, on stolons of Myrionema amboinense Pictet, 1893; 18.03.2008 —numerous sterile colonies, on Thalassia testudinum; 20.03.2008 —one dense, sterile colony, on T. testudinum; 21.03.2008 —numerous sterile colonies, on T. testudinum (MHNG INVE 60979); 31.03.2008 —two sterile colonies, on T. testudinum . Stn. 6: 28.03.2008 —several sterile colonies, on T. testudinum . Stn. 7: 25.03.2008 —a small, sterile colony, on stolons of Sertularia marginata Kirchenpauer, 1864; 27.03.2008 —a few small, sterile colonies, on various algae.

Type locality. Mangrove Bay, Bermuda.

Remarks. I have little to add to the accurate descriptions given by Calder (1986, 1991d). The category to which the nematocysts of this species belong has not been determined previously (Calder 1991d). However, the cnidome could be examined in the present material, and the two types of nematocysts are: microbasic euryteles (7.4–7.9) × (1.8–2.1) µm undischarged, (8.6–8.8) × (1.9–2.1) µm discharged; macrobasic amastigophores (25.0–26.3) × (10.0–10.5) µm undischarged, (22.6–23.0) × (8.4–9.1) µm discharged. No gonothecae have been found in our material and they are still to be discovered.

Distribution. Western Atlantic (Calder 1991d).