Polycarpa insulsa (Sluiter, 1898)

Figs 13–14

Polycarpa circumarata Van Name, 1921

Polycarpa insulsa: Van der Sloot 1969 and synonymy; Millar 1978, Guyana; Monniot C. 1987, New Caledonia; Monniot et al 2001, South Africa; Rocha et al. 2005, Panama; Rocha, Zanata &Moreno 2012, Mexico, Cuba, Panama, Columbia, Venezuela, Guyana, Suriname.

Stations: AB 161; AR 121; AR178; AR 180. (MNHN S1 POL.B 583)

All specimens have a thick wrinkled tunic with abundant epibionts. The siphon apertures are hardly visible from outside. The body wall is easily extracted from the tunic; it is white opaque and thick with a pink ring at the siphon edge. Internally the siphons have a wide red velum. Some thread like papillae are found on the oral velum, but numerous pointed papillae cover the atrial velum (Fig.13B). The dorsal tubercle is particularly thick and protruding opening in a S (Fig.13A). The branchial sac has 4 folds on each side (Fig. 14) and transverse vessels in several orders of size, some very thick. The dermato-branchial bridges are also opaque and thick. There are no parastigmatic vessels. One branchial formula on the right side is:

Right E - 3 (19) 5 (20) 4 (24) 4 (25) 5 - DL left

The digestive tract occupies ½ of the left body side and is attached to the body wall (Fig.13C). The stomach wall is thick and opaque; it has no caecum. The primary loop is short, closed and contains a foliated endocarp. The rectum ends in a minutely lobed anus. The gonads are numerous, included into the body wall and slightly projecting at its surface (Fig. 13C). The polycarps are elongated, of irregular outline, often associated in a common envelope looking as ramified; they occupy the whole internal side of the body (Fig. 13C). Numerous endocarps are scattered between the polycarps.

This description is similar to that given by Van der Sloot (1969) and by Van Name (1945) for Polycarpa circumarata which is a junior synonym.