(Figs. 3B–C, 4A)
Localities. Cala Sant’Andrea, Asinara National Park, Sardinia, Italy (41°00’48”N; 8°14’56”E) Sand from 2 m deep (Sep. 27, 2014): Type locality. Cala dei Ponzesi, Asinara National Park, Sardinia, Italy (41°05’14”N; 08°20’45”E) Sand from the intertidal (Sep. 30, 2014).
Material. Observations on live specimens. Two whole mounts, one of which designated holotype (FMNH KV.691), the other deposited in the HU XIV.3.06.
Etymology. Species named after the National Park and island of Asinara, Sardinia, where the species was discovered.
Description. Specimens are transparent, unpigmented. A pair of round eyes (Fig. 4A: e) is present anteriorly. The overall internal organisation of the specimens corresponds to that of Orostylis dohae sp. nov. The mouth is situated ventrally, near the anterior body end. A horizontally positioned cylindrical pharynx (Fig. 4A: ph) is situated in the anterior third of the body. The anterior edge of the pharynx bears several small papillae, but long tentacles as in O. dohae sp. nov. were not observed.
The single testis (Fig. 4A: t) is situated ventrally around the midbody. The male copulatory system lies alongside the pharynx. It consists of a large copulatory bulb containing a seminal vesicle (Fig. 4A: sv) and prostatic vesicle. In live specimens, circular muscles clearly surround the copulatory bulb. The seminal and prostate vesicles enter the stylet separately. The stylet (Figs. 3B,C; 4A: st) is a strongly curved, “raptor-claw”-shaped, hollow spine, with a “handle-like” extension projecting proximally. In one of the specimens (HU XIV.3.06), the stylet is straighter, with the distal third bent to one side (Fig. 3C). The total stylet (incl. the handle) measures 64–76 μm (x = 70 μm; n = 2). The handle is 15–19 µm long (x = 17 μm; n = 2). The stylet shows a longitudinal slit on one side. Based on observations of live specimens, it is likely that the male system opens into the oral cavity, as is the case in O. dohae sp. nov.
An ovary (Fig. 4A: ov) was observed in the midbody. It is large and, together with the intestine, takes up most of the posterior two thirds of the body. A single vitellarium fills the caudal end of the body, with two large branches stretching forwards up to the level of the copulatory organ.