Triforis rufula Watson, 1886

Albano, Paolo G., Bakker, Piet A. J. & Sabelli, Bruno, 2019, Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Natural History Museum of the United Kingdom, London, Zoosystematics and Evolution 95 (1), pp. 161-308 : 161

Triforis rufula Watson, 1886

Figure 117

Triforis rufula Watson (1886): 566-567, pl. XLII, fig. 2.

Type locality.

"Lat. 10°30'S, long. 142°18'E. Off Wednesday Island, Cape York, North-east Australia".

Type material.

Lectotype: NHMUK 1887.2.9.1768, here designated. Paralectotypes: NHMUK 1887.2.9.1769-71: 3 specimens (at least one certainly not belonging to this species, see remarks) .

Original description.

Station 186. September 8, 1874. Lat. 10°30'S., long. 142°18'E. Off Wednesday Island, Cape York, North-east Australia. 8 fathoms. Coral mud.

Shell.- High, ruddyish, with convexly conical outlines, a slightly convex base, three rows of tubercles on each whorl, a small furrowed suture, and a conical and high apex. Sculpture: Longitudinals-there are on the last whorl about 18 (on the earlier whorls fewer) direct riblets, which run down the spire pretty continuously, and cross the base; the parting furrows are wide open and rounded. Spirals-on each whorl there are three very slightly raised square threads, which swell into strongish tubercles as they cross the riblets; they are parted by squarish somewhat narrower furrows; at the angle of the base, barely within its contraction, is a slightly weaker subtubercled thread; another, weaker and undulated rather than tubercled, occupies the middle of the base; round the top of the pillar is another weaker still. Colour yellow, more or less ruddy. Spire high, very slightly tumid, the lateral outlines being convex. Apex has a small blunt rounded tip, is translucent white and conical, and consists of five short convex whorls, on each of which, above the middle, are two fine flat slightly raised threads; their surface is also scored longitudinally with fine regular bard. Whorls 8, besides those of the apex; they are flat on the sides, of slow and regular increase, and are parted by a strong sutural furrow; the last whorl is little larger than the penultimate, and has a short rounded base. Suture oblique, strongly defined by its furrow, but in itself invisible. Mouth oblique, irregularly four-sided, very acute-angled above at the sinus, and below at the canal. Outer lip thin and sharp, angulated but not sinuated at its insertion; from this point its edge advances all the way to the base of the shell, at the corner of which it turns in a distinct angle, and across which it is prominent; the lip of the canal does not touch the pillar point, so that the round canal is not closed. Pillar short, twisted but very shortly reverted at the point. Inner lip well defined, with a slightly thickened edge, concave. H. 0.192 in. B. 0.057. Mouth, height 0.037, breadth 0.027. Apex, height 0.02, breadth 0.014.

This species is in a vague way very like a great many others of the genus, but is distinct from any known to me.

Diagnosis.

Lectotype 4.2 mm high. Shell cyrtoconoid with flat whorls. Teleoconch of eight whorls with three spiral cords well developed from the first whorl onward and bearing tubercles at the intersection with orthocline axial ribs. A fourth smooth suprasutural cord is visible in the lower half of the shell. Growth lines are visible between the cords. Peristome incomplete in the lectotype. Siphonal canal short. On the base, the fourth cord becomes strong and slightly tubercled and two more smooth cords are visible. Protoconch multispiral of at least four whorls, but the first whorls are missing. These whorls bear two spiral keels and axial riblets. Teleoconch brown, protoconch white.

Remarks.

Lot NHMUK 1887.2.9.1768-71 contains four specimens, with one specimen clearly matching the original drawing. Another specimen is obviously not conspecific because it has the second spiral cord developing later along the spire in contrast to T. rufula in which the three spiral cords are evident throughout the teleoconch. The other two specimens are juveniles and difficult to associate to this taxon due to their state of preservation. A lectotype is designated to stabilise the nomenclature.

Figures

Figure 117. Triforis rufula Watson, 1886, off Wednesday Is., Cape York, north-east Australia. A, E Original figures B-D, F-H Lectotype NHMUK 1887.2.9.1768: front (B, C), side (D), protoconch (F), aperture (G), peristome (H). I. Original labels. Scale bars: B-D: 1 mm; F: 0.2 mm; G, H: 0.5 mm.