(van Beneden, 1913)
Solitary zooids: up to 70 mm long (Ihlea racovitzai, Ihlea racovitzai 1). Seven body muscles, MI to MVI broad and continuous. Dorsally, MI to MIV and MV to MVI medially contiguous over a wide area of contact, forming two groups. MI to MV contiguous ventrally only in the midline. MI nearing MII in the form of a pronounced spur. MIV and MV converging and becoming contiguous laterally. MVII divided into two branches, barely contiguous in the mid-dorsal region and interrupted ventrally. Muscular fibers in the central part of the muscles, small and tightly packed (cannot be counted). Stolon exiting ventrally through an opening located behind and to the left of the nucleus.
Aggregate zooids: up to 20 mm long (Ihlea racovitzai 2, Ihlea racovitzai 3). Five body muscles. MI to MIII contiguous dorsally over a wide area, MIV to MV likewise. MIII and MIV contiguous laterally on one side or the other, depending on the asymmetry. MV divided into two short branches on one side, and producing two long branches, ventrally directed and interrupted, on the other side. MII to MIII fused ventrally with MIV. Number of muscular fibers of MII: 60-92. Two embryos behind MIV.