New Pleistocene Neogastropoda from the New Hebrides.

This record provides an [OPEN-ACCESS] scholarly reference copy of:

Ladd, H. S. (1976). New Pleistocene Neogastropoda from the New Hebrides. The Nautilus 90(4): 127–138 (published [29 October 1976]), figs. [1–40].

[Scope and significance]

The paper presents a focused systematic treatment of exceptionally well-preserved [PLEISTOCENE] [NEOGASTROPODA] from [ESPIRITU SANTO (SANTO)], [NEW HEBRIDES (VANUATU)]. It establishes [ONE NEW GENUS] and [ELEVEN NEW SPECIES] across multiple neogastropod families and documents additional noteworthy taxa from the Santo assemblage. The contribution represents an early taxonomic release from a larger ongoing study of the New Hebrides fossil molluscan fauna.

[Geological and geographic context]

Material derives from highly fossiliferous river exposures of the [NAVAKA SANDS] and the [KERE SHELL BED] on Espiritu Santo. Principal mapped localities include:
• [SM242] (Kere River): 166°55.74′E, 15°34′S; altitude ~70 m; corresponding to [USGS CENOZOIC LOCALITIES 25715 AND 25718].
• [SM43] (Navaka River): 166°51.04′E, 15°36.08′S; altitude ~50 m; associated with [USGS LOCALITIES 25731, 25736, AND 25742].

An additional collecting point ([SG79]; Sarakata River drainage) is discussed in the text but not plotted on the original locality map.

[Stratigraphy, palaeoecology, and age]

The fossiliferous units include the [NAVAKA SANDS] (historically including Mawson’s “Tasiriki foundation-beds”) and the [KERE SHELL BED], a grey silt composed of approximately [50–70%] calcareous skeletal material with an observed thickness of at least [1 m].

Palaeoecological interpretation indicates deposition in [MODERATE-DEPTH, OFF-REEF SHELF] settings, with preferred depths exceeding [~50 m]. The relatively high proportion of newly described taxa is interpreted by the author as likely reflecting limited knowledge of comparable modern faunas rather than great antiquity.

A [PLEISTOCENE] age is supported by planktonic foraminifera (including [Globorotalia truncatulinoides]) and coral dates from [SM242] ([U–Th ~14 ka]; radiocarbon [25,280 ± 460 years]).

[Coralliophilinae focus (IMS indexing)]

Of particular relevance to coralliophiline systematics, the paper establishes two taxa currently retained within [MURICIDAE: CORALLIOPHILINAE]:

1. [Coralliophila mallicki] Ladd, 1976 — new species (pp. [128–130], figs. [5–7]; [AphiaID: 709214]).
   Holotype: [USNM 214348] from [SM242-444A] (Kere River).
   Dimensions: height [11.9 mm]; diameter [10.0 mm].
   Occurrence: single specimen from the [KERE SHELL BED].
   Etymology honors [Dr. D. I. J. Mallick].

2. [Latiaxis (Tolema) blowi] Ladd, 1976 — new species (p. [130], figs. [2–4]), currently accepted as [Babelomurex blowi] (Ladd, 1976) ([AphiaID: 709425]).
   Holotype (only specimen): [USNM 214250].
   Dimensions: height [28.0 mm]; diameter [18.3 mm].
   Type locality: [USGS LOCALITY 25715], Kere River.
   Named for [Warren Blow] (USGS).

[Taxonomic output and illustrations]

The publication illustrates the treated taxa in a comprehensive figure series (Figs. [1–40]), including detailed views of protoconchs and shell sculpture. Notably, the genus [Bathynassa] is documented using [SCANNING ELECTRON MICROSCOPY] (Figs. [38–40]).

According to MolluscaBase ([SourceID: 136543]), [THIRTEEN TAXON RECORDS] are currently linked to this publication, representing the original species-group descriptions and subsequent taxonomic treatments.

[Provenance]

Material studied derives from coordinated field investigations of the [NEW HEBRIDES CONDOMINIUM GEOLOGICAL SURVEY] and subsequent [SMITHSONIAN/USGS] work. The author acknowledges contributions from [Mallick], [Greenbaum], [Waller], and [Blow] in the discovery and documentation of the Santo fossil assemblages.

[Rights and source note]

The original article was digitized and made publicly available by the [BIODIVERSITY HERITAGE LIBRARY (BHL)] with permission of the rights holder ([BAILEY-MATTHEWS NATIONAL SHELL MUSEUM]). This Zenodo record redistributes the publicly available scan to support taxonomic verification, nomenclatural research, and long-term bibliographic preservation within the [INSTITUTE FOR MOLLUSCAN SYSTEMATICS (IMS)], Tenerife. Reuse remains subject to the applicable license and rights statements.