Limipolycystis wallbergi n. sp. Artois, Willems & Schockaert

(Figs 3 G–H, 4C–D)

Holotype. A whole mount, Italy, Sardinia, Capo Caccia, eastern side of the cape, coarse-grained sand, 20–25 m deep, 30 March 2010 (SMNH Type-8316).

Other material. One whole mount and one sectioned specimen, France, Banyuls-sur-Mer, northeast from Ile Grosse, 42°28'57.81"N 3°8'15.42"E, pure, relatively fine sand, 12 m deep, 06 August 2007 (HU V.2.49–50). Live observations on one animal, Italy, Sardinia, Budelli Island, Il Cavaliere, 41°17’29.76”N 9°20’52.04”E medium- to fine-grained, clean sand, 33–37 m deep, 7 September 2010.

Etymology. Species name dedicated to Dr Andreas Wallberg, a colleague and dear friend of W. Willems.

Diagnosis. Species of Limipolycystis with two eyes. Prostate vesicle of type III, well developed. Stylet an accessory stylet of type II, tubular, 127–153 µm long, robust, straight, with obliquely cut-off distal end, a small plateshaped part protruding proximally from the stylet opening and one spirally-running ridge over the whole length.

Description. Uncoloured animals with two eyes, ± 1 mm long. Habitus and general organization similar to that of other species of Limipolycystis.

In live animals, the testis is relatively large, extending from just behind the pharynx towards the most caudal body end. The prostate vesicle is large, globular, and contains two types of eosinophilic glands: one darkly stained, the other lightly stained. The stylet is a rather robust, straight tube with a ridge running spirally over most of its length. It is 139 µm and 158 µm long in the whole-mounted specimens from Capo Caccia and Banyuls respectively; 149 µm measured on photographs of the live specimen from Budelli Island. Distally it ends in a sharp hook. In the holotype the most distal part of the stylet is deformed, but from live observations it is clear that this distal part is exactly the same as that of the specimens from Budelli Island and Banyuls, the latter depicted in Fig. 3 G. The proximal part has a thickened wall, provided with some ridges. Proximally from the proximal stylet opening, the stylet shows a relatively small projection (indicated with an arrow on Figs 3 G–H, 4C), which is somewhat coffee-cup shaped. In the specimen from Banyuls, this coffee cup shape cannot be seen. This could indicate that the population from Banyuls is morphologically different from the Italian populations, but pending observations on more specimens, we prefer to keep the three populations within one species. The seminal receptacle could not be observed on the live specimens, nor on the sections, which are of mediocre quality.