Hyperioides sibaginis (Stebbing 1888)

Hyperioides sibaginis (Stebbing)

Hyperia sibaginis Stebbing, 1888:1379–1382, pl. 165.–Bovallius, 1889:201–203.–Barnard, 1931:127–128.–Chiba, Tsurutu, and Maeda, 1955:194, 196, 200.

Hyperia sibaginis ? Stebbing.–Pirlot, 1930:18–19, fig. 6.

[not] Hyperia sibaginis ? Stebb.–Vosseler, 1901 [=H. longipes Chevreux].

DERIVATION OF NAME.–Not expressly stated, but presumably for Sibago Island, Philippines.

TYPE-LOCALITY.–Challenger station 200, northeast of Sibago Island, east of Zamboango Peninsula, Philippines: 6°47′N, 122°28′E.

DIAGNOSIS.–Both species of Hyperioides have been well described and illustrated, and in view of the ease with which this genus may be identified, diagnoses of its two species may be presented conveniently by the following tabular comparison.

IV. Lestrigonus Milne Edwards

Lestrigonus Milne Edwards, 1830:392; 1840:81–82.

DIAGNOSIS.–Small species, with rather plump pereon. Head globular; eyes occupying most of its surface. Some of anterior pereonites fused (2?), 3–5 in ♀, 2–4 in ♂, always more in ♀. Coxae fused with pereonites. Telson of moderate size. ♀ A1 2–merous. ♀ A2 1–merous, usually very small; gland cone conspicuous, with pointed or rounded apex. Epistome prominent, strongly convex anteriorly. Md with dentate incisor; palp absent in ♀. MX1 outer lobe with 3 large terminal spines and usually a smaller subterminal spine. Mxp outer lobes separate, tapering distally; inner lobe usually well developed. P1 subchelate or barely chelate. P2 distinctly chelate; carpal process spoon-shaped, with spines along margin of spoon. P5–7 usually longer than P3–4; P5 and P7 subequal, slightly shorter than P6.

DERIVATION OF NAME.–“Seemingly from , an ancient savage tribe of Italy and Sicily” (Stebbing, 1888). Gender, masculine.

TYPE-SPECIES.–By monotypy, Lestrigonus fabrei H. Milne Edwards, 1830.

REMARKS.–Next to Hyperia, Lestrigonus is the oldest available generic name for this group of species. Since Hyperia is restricted herein to a different group of species, Lestrigonus becomes the valid name of the genus, and L. fabrei is automatically the type-species. This is not an ideal situation, since the true identity of L. fabrei is uncertain. The species called Hyperia fabrei by most authors is an entirely different species, H. vosseleri Stebbing, which I am transferring herein to the new genus Hyperietta. The true Lestrigonus fabrei has not been recorded since the original accounts by Milne Edwards (1830, 1838, 1840), which were limited to the male. Milne Edwards unfortunately gives little information concerning the characters that I have found most useful for distinguishing genera and species of Hyperia s.l. His illustrations (1840) include a lateral view of the male and drawings of the Md and Mxp; copies of these drawings are given in Figure 27. I am unable to add any details because the type-specimen appears to have been lost. Dr. J. Forest, Muséum National d’Histoire Naturelle, Paris, has kindly informed me that a vial containing a label reading “Lestrigonus fabrei. Mer des Indes. Raynaud coll.” contains a second label in the handwriting of Bouvier stating that the vial was returned empty by Bovallius. For the time being L. fabrei remains a nomem dubium.

Milne Edwards’ species can be excluded without difficulty from the genera of Hyperiidae other than Lestrigonus considered herein. Following each genus in the list below, I give the characters of L. fabrei that exclude it from that genus.

Hyperia and Hypericlla: Pereonites 1–2 fused; coxae fused with pereonites.

Hyperioides: P5–7 subequal.

Themis tella: Pereonites 1–2 fused; P5–7 subequal; Mxp with well-developed inner lobe.

Hyperietta: Mxp with long narrow outer lobes and well-developed inner lobe; no long spines on s4–5 of P3–4.

Hyperionyx: Mxp with long narrow outer lobes; P5–7 subequal.

Only the rediscovery of Lestrigonus fabrei will enable us to know with certainty whether it agrees with the details in my emended diagnosis of Lestrigonus. There is nothing seriously incompatible with this diagnosis in Milne Edwards’ description and illustrations except possibly the body length cited by him, “long d’environ cinq lignes.” This length is about 11 mm, much longer than the species herein assigned to Lestrigonus, which rarely exceeds 4 mm. I suspect, but cannot prove, that Milne Edwards’ measurement was inaccurate.

Attempting to sort out the valid species of Lestrigonus and their synonyms from published descriptions and illustrations has been very frustrating. In some instances previous authors assigned males and females or adults and juveniles of one species to different species or even different genera. Much of the confusion can be attributed to the fact that these authors, following Bovallius, used the number of fused pereonites as a primary character for separating species, but failed to realize that in any species the fusion is greater in females than in males and greater in juveniles than in adults. One can scarcely blame Pirlot (1939) for retreating from the resultant problem by reducing most of the species herein assigned to Lestrigonus to synonyms of Hyperia bengalensis. Pirlot’s action only added to the confusion, and unfortunately a number of subsequent workers have preferred to take refuge in his synonymy rather than to attempt the formidable task of sorting out the valid synonyms without the aid of adequate collections.