Bellaspira Conrad, 1868

Fallon, Phillip J., 2016, Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species, Zootaxa 4090 (1), pp. 1-363 : 23-24

Genus Bellaspira Conrad, 1868 , redefined by McLean & Poorman (1970: 1–3).

Type species by monotypy: Mangelia virginiana Conrad, 1862 , Yorktown Formation, Virginia [Late Miocene, Early to Middle Pliocene (Hazel, 1971; Cronin, 1991)].

McLean & Poorman (1970: 3) clarified the diagnosis for the genus, which had become muddled on account of the mislabeling of an unrelated species as the type of the genus, and its subsequent incorrect association by Bartsch with other species.

Diagnosis. Shell fusiform, glossy, with low round-crested axial ribs that extend to the suture, lower in and sharply demarcated by the sulcus in some species. Protoconch with approximately 2 smooth whorls. Shell surface with incised lines or threads. Anal sinus is a wide, shallow indentation of the outer lip on the shoulder near the suture (when shell is viewed laterally), and a narrow inverted “V” at the junction of the outer lip and suture with a callus on both sides (when shell is viewed ventrally). Outer lip thin; varix like a thickened rib or broad and humplike. Anterior canal broad, slightly notched, and curved to the left (shell viewed ventrally). Color variable but generally a white, pink, or light brown base with a brown, pink, or orange band mid-whorl that may be broken by the ribs. Operculum is leaf-shaped with a terminal nucleus; radula typical for the family.

Key characteristics. The presence of all the following characteristics is diagnostic of Bellaspira and separate the genus from all other TWA Drilliidae :

1. Anal sinus is a shallow and wide indentation of the outer lip beginning at the suture (when shell is viewed laterally), and shaped like an inverted “V” with inner callus on both sides of mature specimens (when shell is viewed ventrally); and

2. Surface microsculpture of widely spaced spiral incised lines or faint threads over most of the teleoconch (usually spaced closer on the shoulder) with irregularly spaced microscopic growth striae visible between them; spiral ridges or fine threads present on the shell base and anterior fasciole.

3. Axial ribs extend from suture-to-suture, and only slightly changed on the shoulder of most. A few species have a groove or ridge followed by lower ribs at the anterior boundary of the sulcus.

Similar genera. Splendrillia is similar but possesses a different anal sinus, ribs that do not reach the suture, and a hump-like varix ⅓-turn from the edge of the outer lip, not an enlarged rib. A heavily spirally grooved form of Bellaspira margaritensis McLean & Poorman, 1970 may appear to be a Clathrodrillia but members of the latter genus possess more angular shoulders, a spout-like anal sinus, and other differences.

Distribution. Bellaspira is restricted to the Americas; McLean & Poorman (1970) reviewed the six thenknown species from the Caribbean, Panamic, and Californian provinces; the two from the Caribbean being Bellaspira margaritensis McLean & Poorman, 1970 and Bellaspira pentagonalis (Dall, 1889) . The present work significantly increases the census of western Atlantic species and extends their distribution to off south central Brazil of the Brazilian province. Species of Bellaspira are now known to be widely distributed in the TWA region, from North Carolina to south central Brazil, westward to Colombia in the southern Caribbean and in the western Gulf of Mexico (see Plate 14 ). Curiously though, they appear to be mostly absent from shallow reefal areas of the central Caribbean Basin, including the Greater and Lesser Antilles and Central America south of the Yucatan peninsula. This pattern is may be a result of sampling bias, but their distribution suggests a habitat preference for subtropical waters (North Carolina, Florida and the Gulf of Mexico, and south-central Brazil. A few species, Bellaspira hannyae (Jong & Coomans, 1988) , B. margaritensis and B. pentagonalis are found regularly in shallower water (30–80 m) on the continental shelf of the north coast of South America.

Figures

PLATE 14. Bellaspira stahlschmidti, new species. Figs. 1 – 3: holotype, off Guarapari, Espirito Santo, Brazil (MZSP 122054). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, L = edge of lip, V = edge of outer lip.