VENUS 71 (1–2): 13–27, 2013 ©Ma lacological Society of Japan

On the Recent Members of the Vermeij, 1991 in the Northern Pacific, with Description of a New (: )

Paul Callomon* and Amanda S. Lawless Academy of Natural Sciences of Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, PA 19103-1195, USA

Abstract: A review is made of the Recent memb ers of the buccinid genus Lirabuccinum Vermeij, 1991, to which is added a new species from the Yellow Sea. Placement in the genus and the family Buccinidae is confirmed on the basis of radular and morphology. There is a discussion of shell structure, with reference to the independent development of internal and external spiral sculpture. Lectotype selections are made for Searlesia constricta Dall, 1918, Euthria hokkaidonis Pilsbry, 1901 and E. fuscolabiata E. A. Smith, 1875.

Keywords: Buccinidae, Lirabuccinum, new species, musculus, Japan, China, Yellow Sea

Introduction

In 2008, some cleaned shells were obtained by the authors from sources in China that apparently represented a new species. They were initially thought to be fasciolariids but also showed buccinid affinities. Through the kind offices of Mr. Donald Dan, alcohol-preserved specimens were then obtained from the same locality, and the radula confirmed placement in the Buccinidae. Examination of many specimens suggested placement in the genus Lirabuccinum Vermeij, 1991. The Recent species of the genus are here reviewed, with emphasis on shell structure and radular characters. Pending re-examination of the relevant material, the fossil memb ers of the genus are retained as in Amano & Vermeij (2003).

Abbreviations used: AM, Australian Museum, Sydney; ANSP, Academy of Natural Sciences, Philadelphia, USA; BM NH, The Natural History Museum, London, UK; M NHN, Museum national d’Histoire Naturelle, Paris, France; NMNH, National Museum of Natural History, Smithsonian Institution, Washington DC; NSMT, National Museum of Nature and Science, Tokyo, Japan; SL, shell length; SMF, Senckenberg Forschungsinstitut und Naturmuseum, Frankfurt, Germany; USNM, National Museum of Natural History, Smithsonian Institution, Washington DC, USA.

Materials and Methods

Samples were obtained of all the taxa examined here, either as dry shells or as complete alcohol-preserved specimens, including all extant primary types. The shells of several preserved specimens were cracked using a hand vice and the animal dissected to extract the radula. Two radulae were mounted on stubs and photographed in a scanning electron microscope by Dr. E. Strong (NMNH) . Two more in the ANSP collection that had previously been extracted and

* Corresponding author: [email protected] 14 P. Callomon & A. S. Lawless mounted on slides were sketched from photographs taken under a Leitz examining microscope by Dr. B. Rinkel (ANSP). The remainder were extracted by the authors, mounted in Euparal on glass slides and sketched using a Bausch & Lomb compound microscope with a camera lucida. Shells were sectioned through the terminal bank of lirae behind the apertural lip (L. musculus, L. fuscolabiatum) or at an equivalent point (L. dirum), and through the upper body whorl roughly 180º from and parallel to the first section. Cuts were made with a file or grinder and the sections polished using 2400 grit carborundum paste. The section planes were photographed under normal light through a Bausch and Lomb compound microscope at 80x magnification.

Terminology: The spiral sculpture of the shell consists of two independent elements; cords formed in the external shell layer and lirae formed in the internal layer, hereafter referred to as “cords” and “lirae”.

Systematics

Family Buccinidae Rafinesque, 1815 Genus Lirabuccinum Vermeij, 1991 Type species: dirum Reeve, 1846, by original designation.

Lirabuccinum dirum (Reeve, 1846) (Figs. 1–3, 15, 18, 26)

Buccinum dirum Reeve, 1846: pl. 12, sp. 92. Searlesia dira (Reeve, 1846) – Dall, 1918: 98, pl. 8, fig. 1; Abbott, 1974: 216, no. 2390; Abbott & Dance, 1982: 169, bottom left fig.; Vermeij, 1991: 267, figs. c, d.

Type material: Reeve’s figured type of Buccinum dirum was originally in the Cuming Collection. It is apparently not present in the BMNH (K. Way, pers. comm.). The putative type specimens there all have intact apices, whereas the shell in Reeve’s figure (Fig. 1) clearly is decollate. Material examined: California, USA: Bolinas, Marin County, ANSP 34784 (2), 34786 (4), ANSP 225992 (2), ANSP 221938 (3); Oregon, USA: Otter Rock, near Newport, ANSP 131061 (12), ANSP 139918 (6). Cape Arago, ANSP 350429 (1). Washington State, USA: Juan de Fuca Strait at Sekiu, ANSP A17014 (3); Juan de Fuca Strait, ANSP 34788 (1); Rosario Beach, Anacortes, Fidalgo Island ANSP 410821 (1); Neah Bay, ANSP 46054 (2); Clallam Bay Lighthouse, ANSP 300604 (1); Smallpox Bay, San Juan Id., ANSP 395028 (3), ANSP 395029 (3); San Juan Id., ANSP 46053 (2). Alaska, USA: Sitka, ANSP 34503 (1); Tongass Island, ANSP 34787 (5); Washington Bay, Kuiu Island, ANSP 401544 (2). British Columbia, Canada: Vancouver Island, ANSP 34785 (3), ANSP 395030 (2); Victoria, ANSP 65867 (2); Kachemak Bay at Seldovia, ANSP 243934 (1); Annette Island, ANSP 182737 (8), ANSP 181433 (4) (Figs. 26, 30); Langara Island, ANSP 152358 (7); Banal Island, ANSP 351423 (4); Maple Bay, Vancouver, ANSP 351424 (2). Distribution: L. dirum is known over a wide range of the northern Pacific coast of North America, from California to Alaska; the westernmost record is from Chirikof Island (55°49´30˝N, 155°37´19˝W; Dall, 1918). It is not present in Japan, the Kuril Islands, the Okhotsk Sea or the Aleutians. Description: Shell to 48.8 mm SL (average adult size 35.14 mm SL, n = 40), very thick and robust, of six whorls, buccinoid in shape. Protoconch smooth, approximately 2 whorls, though all examined protoconchs incomplete. First teleoconch whorls bear broad axial ribs with deep A New Species of Lirabuccinum (Gastropoda: Buccinidae) 15

Figs. 1–3. (Reeve, 1846). 1. Original figure of Buccinum dirum (Reeve, 1846: sp. 92). 2. San Juan Id., Washington, USA. ANSP 46053, 48.5 mm SL. 3. Vancouver Island, Canada, ANSP 395030, 38.4 mm SL. Figs. 4–6. Lirabuccinum fuscolabiatum (E. A. Smith, 1875). 4. Lectotype of Euthria fuscolabiata E. A. Smith, 1875, BMNH 1873.8.6.25, 28.7 mm SL. 5. Lectotype of Fusus modestus Gould, 1860, USNM 1649, 18.4 mm SL. 6. Lectotype of Searlesia constricta Dall, 1918, USNM 274072, 29.6 mm SL. Figs. 7–9. Lirabuccinum hokkaidonis (Pilsbry, 1901). 7. Lectotype, ANSP 80394, 22.1 mm SL. 8. Paralectotype, ANSP 426452, 22.5 mm SL. 9. Hariusu, Hokkaido, Japan, ANSP 279967, 23.4 mm SL. Figs. 1–9 at the same scale. 16 P. Callomon & A. S. Lawless

Figs. 10–14. Fusinus musculus n. sp. (All specimens from type locality). 10. Holotype, ANSP 424655, 38.5 mm SL. 11. Paratype 1, ANSP 424656, 41.1 mm SL. 12. Paratype 2, ANSP 424656, 41.8 mm SL. 13. Paratype 3, ANSP 424656, 42.9 mm SL. 14. Paratype 4, ANSP 424656, 36.7 mm SL. All figures at the same scale, except 11C, 11D and 14C. A New Species of Lirabuccinum (Gastropoda: Buccinidae) 17

Fig. 15. Lirabuccinum dirum, animal (partial), Juan de Fuca Strait at Sekiu, Clallam County, Washington, USA, ANSP A17014. Fig. 16. Lirabuccinum musculus, animal of paratype 9 (partial), ANSP A22015. Fig. 17. Lirabuccinum fuscolabiatum, animal (partial), off Satsukari, Hokkaido, Japan, NSMT. Figs. 15–17 at the same scale. interstices. Ribs regularly spaced until penultimate whorl, becoming reduced and scattered; absent on body whorl. First teleoconch whorl lacks spiral sculpture. Approximately nine tightly packed major spiral cords begin on second whorl and extend through body whorl, overriding axial ribs. Suture adpressed; no resorbtion or similar bonding occurs at point where suture overrides sculpture of preceding whorl. Aperture over half length of shell, pinched at posterior terminus. Profile of lip smoothly curved. Neck short and stout. Labral wall of aperture bears strong spiral lirae that lie on crowns of crenulations; lirae run entire length of shell interior but terminate approximately one-third whorl from lip (see Remarks). Lip margin thin and corrugated with slight dentition at termini of cords. 18 P. Callomon & A. S. Lawless

Fig. 18. Lirabuccinum dirum; scanning electron micrographs of radula (A) and detail of rachidian tooth (B), from animal in Fig. 15. Scale bar (A) = 100 mm. Figs. 19–20. Lirabuccinum fuscolabiatum, radula. 19. “Japan”, ANSP 58062. 20. Off Satsukari, Hokkaido, NSMT. Scale bar = 100 mm. Figs. 21–23. Lirabuccinum musculus radula. 21. Scanning electron micrographs, from type locality. 22. Detail of tricuspid rachidian and lateral with less developed afferent cusp, ANSP A22015. 23. Two rows from same radula, showing variation in development of rachidian cusps and afferent cusps on laterals, ANSP A22015. Scale: Fig. 21, 100 mm; Figs. 22–23, as Fig. 20. A New Species of Lirabuccinum (Gastropoda: Buccinidae) 19

Parietal wall of aperture smooth, thickly glazed in anterior half; some resorbtion of spiral sculpture in anterior part, but posteriormost 4–5 major cords persist into shell in juvenile examples. Two or three superimposed short spiral lirae at posterior part of aperture in adults. Labral margin smooth, except where thickening produces distinct margin in anterior third. Canal broad and open. Shell exterior pale gray-brown to dark brown; interior of aperture pale reddish brown to off- white, usually with broad band of darker brown at labral margin. thin, medium to dark brown, with nucleus at anterior terminus. Animal (Fig. 15): Head broad, with widely spaced cylindrical tentacles bearing eyes on outer margin at base. Large penis posterior to head on right side. Upper surface of foot covered with rough papillae. Proboscis long, narrow, with buccal mass in anterior third. Radula (Fig. 18): Three teeth per row. Broad, arcuate rachidian tooth bears three slightly asymmetrical cusps. Lateral tooth of sickle shape with prominent afferent cusp of varying size alongside inner arm. Remarks: Sectioning and examining the shell (Fig. 26) reveals that, in common with other members of the genus, L. dirum deposits its internal lirae independently of the external spiral sculpture. The fine, translucent internal lirae can be hard to see, as they lie on the crowns of the spiral shell crenellations and terminate in long spear-like points some distance inside the aperture. See also Discussion.

Lirabuccinum fuscolabiatum (E. A. Smith, 1875) (Figs. 4–6, 17, 19, 20, 24)

Euthria fuscolabiata E. A. Smith, 1875: 421–422. Fusus modestus Gould, 1860: 327 [non Philippi, 1844]. Searlesia constricta Dall, 1918: 228; Dall, 1921: 98, pl. 8, fig. 1. Euthria fuscolabiata E. A. Smith – Pilsbry, 1895: 34. Searlesia fuscolabiata (Smith) – Y. Hirase, 1908: 37–38 (J), 8 (E), pl. 25, fig. 6; S. Hirase, 1934: 72, pl. 102, fig. 15; Kinoshita, 1934: 9, pl. 7, fig. 48. Searlesia constricta Dall – Kosuge, 1972: pl. 9, fig. 5 (type). Searlesia hokkaidonis (Pilsbry) – Kinoshita, 1937: 14, pl. 4, fig. 20. Non Pilsbry, 1901. Searlesia modesta (Gould, 1860) – Habe, 1961: 62, pl. 31, fig. 15; Okutani, 2000: 487, fig. 160; Min et al., 2004: 230–231, fig. 619.

Type material: Euthria fuscolabiata E. A. Smith, 1875. Five syntypes originally cited; lectotype (incorrectly cited as holotype by Higo et al., 2001 following BMNH notation, and by Amano & Vermeij, 2003), here selected, BM NH 1873.8.6.25, 28.7 mm SL (Fig. 4); paralectotypes in same lot, 28.1, 24.4 & 24.2 mm SL. Fusus modestus Gould, 1860; lectotype, selected by Johnson (1964: 111, pl. 6, fig. 5), USNM 1649, 18.4 mm SL (Fig. 5). Searlesia constricta Dall, 1918; lectotype, here selected, USNM 274072 (29.6 mm SL) (Fig. 6). Material examined (all from Japan): Hokkaido: Off Otaru, ANSP 414314 (3); Hakodate Bay off Satsukari in Kikonai-cho, Oshima Subprefecture, NSMT (15). Iwate Prefecture: Kesen-numa, ANSP 244660 (3); Otomo, ANSP 241294 (2), Rikuzen coast, ANSP 244729 (6). Kanagawa Prefecture: Sagami Bay, ANSP 244730 (3). Kochi Prefecture: Tosa Bay, ANSP 189682 (2). “Japan” ANSP 58062 (1). In addition, 30 lots in the NSMT collection comprising 116 specimens were confirmed as L. fuscolabiatum by Dr. K. Hasegawa. 20 P. Callomon & A. S. Lawless

Distribution: L. fuscolabiatum is known on the Pacific coast of Japan from Hakodate Bay in southeastern Hokkaido to at least Tosa Bay in southern Shikoku and from southern Korea (Gangwon and Gyeongsang Provinces: Min et al., 2006). Records from the Japan Sea are mostly from the area between Otaru on the western coast and the Oga Peninsula in Akita Prefecture, Honshu. Records from further south are sparse, but this species was recorded from the Noto Peninsula on the central Japan Sea coast by Amano & Vermeij (2003). Three possibly fossil specimens are in the NSMT collections from off the Noto Peninsula (NSMT-Mo 435556, R6240) and off the Oki Islands (NSMT-Mo 43559). Description: Shell to 33.6 mm SL; average adult size 29.49 mm SL (n = 14), of seven whorls, fusiform in shape with tall spire and inflated body whorl. Protoconch broken in all material examined; smooth, approximately 2 whorls. No varix apparently present, though beginning of first teleoconch whorl worn in all material examined. First teleoconch whorls bear ten broad axial ribs with interstices wider than ribs. Five major spiral cords on first whorls, forming ridges that override and splay on top of axial ribs. Two minor cords appear between major cords starting on penultimate whorl and onto body whorl. Suture adpressed, with no resorbtion or similar bonding at point where suture overrides sculpture of preceding whorl. Axial microsculpture of dense, fine growth lines over entire teleoconch. Aperture strongly pinched at anterior terminus. Profile of outer lip smoothly curved. Neck short and stout, varying in length. Labral wall of aperture bears distinctive strong spiral lirae that terminate as row of 11–12 pale ridges some way behind lip, present up to terminus of suture; position of lirae not related to crenulations in lip, which reflect termini of spiral cords on outer face. Lirae do not run entire length of shell interior. Lip margin thin, corrugated, but lacking dentition. Parietal wall of aperture smooth, with some resorbtion of spiral sculpture; two short added spiral lirae present at anterior end in adult specimens. Labral margin smooth, except where thickening produces distinct margin in anterior third of canal. Canal broad, open, short and slightly reflected. Shell pale to medium brown overall, with random dark axial patches. Operculum thin, medium to dark brown with nucleus at anterior terminus. Animal (Fig. 17): Head small, with short, triangular lappets bridged by narrow web. Eyes at middle of outer margin of lappets. Large penis on right side anterior to head. Foot relatively smaller than in other members of genus; upper surface smooth. Proboscis long, very narrow. Radula (Figs. 19, 20): Three teeth per row. Arcuate rachidian tooth bears three asymmetrical cusps; laterals simple, sickle-shaped with prominent sharp termini. Remarks: Comparison of the radula of specimens identified as L. fuscolabiatum (Fig. 19) and Fusus modestus (Fig. 20) in the ANSP collection confirms them to be the same species. The degree of variation is less than that seen within a single L. musculus radula (Fig. 23).

Lirabuccinum hokkaidonis (Pilsbry, 1901) (Figs. 7–9)

Euthria hokkaidonis Pilsbry, 1901: 389, pl. 19, fig. 7.

Type material: Euthria hokkaidonis Pilsbry,1901; lectotype, here selected, 22.1 mm SL, ANSP 80394, ex Y. Hirase, 1901 (Fig. 7); paralectotype, from same original lot, 22.5 mm SL, ANSP 426452 (Fig. 8). Material examined: ANSP material: Hariusu, near Otaru, eastern Hokkaido, ANSP 279967, D. Thaanum coll., 1929, 24.1, 23.4 (Fig. 9), 21.0 mm SL. A New Species of Lirabuccinum (Gastropoda: Buccinidae) 21

NSMT material (fide K. Hasegawa): Otaru, Hokkaido, NSMT-Mo 43555 (1), 43557 (1), 43562 (1); Kyuroku Id., Aomori Prefecture, Honshu: 43560 (1); Oga Peninsula Akita Prefecture, 50–80 m, 73442 (2). Type locality: “Nakauta, Teshio”. This is Nakauta in Mashike-cho, Mashike District, Rumoi Subprefecture, northeastern Hokkaido (43°51´N., 141°32´E). There is another place called “Nakauta” in eastern Hokkaido (in Esashi Town, Hiyama district) but this lies far southwards of the old province of Teshio. Description: Shell to 24.1 mm SL (average adult size 22.64 mm SL; n = 5), of seven whorls, slender fusiform in shape with tall spire. Protoconch broken in all material examined; smooth, approximately 1 whorl. Teleoconch whorls bear 12–14 thin axial ribs with instersticial space narrower than ribs. Five major spiral cords on first whorls that override axial ribs, forming elongate lobes. Two minor cords appear between major cords on lower whorls. Whorls separated by deep suture. Axial sculpture of dense, fine growth lines over entire teleoconch. Aperture, canal, labral and parietal walls similar to those of L. fuscolabiatum; L. hokkaidonis has bank of 10 lirae that terminate some way behind lip, and apparently forms internal lirae ad hoc, in the manner of F. fuscolabiatum. Shell pale brown overall, interior of aperture somewhat darker. Remarks: L. hokkaidonis was synonymized with L. modesta (= L. fuscolabiatum) by Kuroda & Kinoshita (1951), but with reference to a figure of the latter (Kinoshita, 1937: pl. 4, fig. 20) that had been misidentified as the former. L. hokkaidonis was treated as a subspecies of fuscolabiatum by Kuroda & Habe (1952: 85), a position adopted by Higo & Goto (1993: 229). Most subsequent authors have synonymized the two, but without figures or references to material. Pilsbry did not publish a picture of the type of L. hokkaidonis, and the first illustration of this species was of the specimen here selected as lectotype, in Higo et al. (2000: 78, no. G3733). The animal is apparently still present in the lectotype, but special techniques will be required to extract the radula from such old dried material. The present authors consider that the two type specimens and one further lot examined are morphologically sufficiently distinct from L. fuscolabiatum as to preclude synonymizing them until further material is obtained. The slender shell of F. hokkaidonis has a taller spire than most L. fuscolabiatum, with finer, more numerous axial ribs. In crossing the ribs, the spiral cords form lobes that are particularly prominent in earlier whorls. The axial ribs in L. hokkaidonis persist onto the body whorl with little or no reduction in frequency or definition, whereas those in L. fuscolabiatum are reduced or absent by the final half of the body whorl. Distribution: All material cited here is from the northern Japan Sea from the northwestern coast of Hokkaido to the Oga Peninsula. This coastline marks the northernmost influence of the weak remnant of the warm Kuroshio surface current that runs along the Japan Sea coast of Honshu and is terminated by the shallow Soya Strait, and L. hokkaidonis might therefore represent a sequestered “end-of-the-line” population. Its distribution overlaps that of L. fuscolabiatum in the area between Otaru in western Hokkaido and the Oga Peninsula.

Lirabuccinum musculus n. sp. (Figs. 10–14, 16, 21–23, 25)

Type material: Holotype, ANSP 424655, 38.5 mm SL (Fig. 10). Paratypes (from type locality): [1] 41.1 mm SL (Fig. 11); [2] 41.8 mm SL (Fig. 12); [3] 42.9 mm SL (Fig. 13); [4] 36.7 mm SL (Fig. 14), ANSP 424656; [5] 43.1mm SL, MNHN; [6] 43.2 mm SL, NSMT; [7] 39.7 mm SL, BMNH; [8] 38.5 mm SL, AM; [9–19] 31.9 (Fig. 16), 36.2, 32.7, 34.9, 34.2, 32.7, 32.2, 29.7, 30.1 mm SL, one unmeasured, alcohol preserved, ANSP A22105; [20] 41.9 mm SL, SMF. 22 P. Callomon & A. S. Lawless

Paratypes (From Yellow Sea, trawled in the north area in 20–80 m, gravel and sand, 2008): [21, 22], 34.4 mm and 37.9 mm (Peter Stahlschmidt collection, Germany, PS-140091). Other material examined: 38.9 mm SL, 42.3 mm SL, 35.4 mm SL, 41.8 mm SL, 36.4 mm SL, 36.6 mm SL, 38.4 mm SL, 39.5 mm SL, 39.8 mm SL, 41.2 mm SL, 41.2 mm SL, 41.7 mm SL, 42.1 mm SL, 42.2 mm SL, ANSP 424657, from type locality; 41.1, 38.4, 41.1, 36.3 & 39.7 mm SL, from type locality, 60 m deep, ANSP 426439. Type locality: Northwestern Yellow Sea off Weihai, Shangdong Province, 30–60 m, on sand bottom. Description: Shell of average size for genus (to 43.2 mm SL; average adult size 40.24 mm SL, n = 23), thin and light, of eight whorls, buccinoid in shape. Protoconch (Figs. 11C, 11D) of approximately 2–3 whorls, first complete whorl 0.6 mm in diameter (see Remarks). First teleoconch whorls bear broad, tapering and tightly packed axial ribs with deep interstices. Ribs become more widely spaced on middle whorls and taper off toward sutures; regularly spaced ribs present until penultimate whorl, becoming scattered and finally absent on body whorl. Seven major spiral cords on first whorls, forming broad lobes in overriding axial ribs. Single prominent minor cord emerges between each major by third whorl; minors multiply and thicken by body whorl, while majors become almost indistinguishable. At least two minors between each major on body whorl, with no gaps remaining. Suture adpressed and heavily rolled; no resorbtion or similar bonding occurs at point where suture overrides sculpture of preceding whorl. Axial sculpture of dense, fine growth lines over entire teleoconch, with frequent growth pauses in final half of body whorl. Aperture ovate to quadrate, strongly pinched at terminus of suture. Profile of outer lip varies from smoothly curved to angular and ventricose. Neck short and stout, varying in length. Labral wall of aperture bears distinctive strong spiral lirae that terminate as row of 7–15 pale ridges some way behind lip, restricted in some specimens to anterior 2/3 of wall, in others present up to terminus of suture; position of lirae not related to crenulations in lip, which reflect termini of spiral cords on outer face. Lirae can be divided into two axial banks (Fig. 5). Lip margin thin, corrugated but lacking dentition; lip somewhat prosocyrt in lateral profile (Fig. 1B). Parietal wall of aperture smooth, thickly glazed in anterior half; some resorbtion of spiral sculpture in anterior part, but posteriormost one or two major cords persist into shell. Labral margin smooth, except where thickening produces distinct margin in posterior half of canal. Canal broad, open, varying considerably in length and width. Shell pale to medium brown overall, with darker growth bands, especially on anterior part of body whorl; extreme margins of anterior end of neck often dark brown. Operculum thin, translucent, yellowish-brown with nucleus at anterior terminus. Animal (Fig. 16): Head small, short with broad, flattened triangular lappets bearing eyes at midpoint of outer margin. Proboscis long, thin, with slightly swollen buccal mass, fully retracted with single z-shaped fold in material examined. Radula (Figs. 21–23): Typical for genus with three teeth per row, but variable. Arcuate rachidian tooth bears three or four cusps; laterals sickle-shaped with prominent sharp termini and single afferent minor cusp on outer shoulder of inner end. Second, very minor cusp occasionally present alongside afferent (Fig. 23A). See also Discussion below. Etymology: musculus (Latin): a mouse, for the small size, rounded shape and brown color. Remarks: All the material here examined is thought to be adult or nearly so, judging from the tightly packed growth margins immediately behind the lip and the thickened, glossy margin of the thickened area at the anterior parietal margin of the aperture. The ratio of height to width varies somewhat in this species, as the final half of the body whorl in many examples flares and becomes somewhat ventricose (e.g., Fig. 3). The apex and first whorls in all the prepared specimens to hand bear patches of thick bitumen, but elsewhere the A New Species of Lirabuccinum (Gastropoda: Buccinidae) 23 outer shell layer has largely been dissolved. The shell material remaining beneath the bitumen residues is soft and friable, suggesting either dissolution by the surrounding water or the use of a corrosive cleaning agent. The unusual glossiness of the early whorls might also be the result of a buffing or polishing process. The specimens were all taken by a small trawler within approximately 30 miles of the shore, and apart from the alcohol-preserved material were prepared by a local specimen dealer. The harder inner part of the protoconch is present in most of the shells examined (Figs. 2C, D), but the outer layer is gone in all of them and details of the exterior of the protoconch, including the manner of its termination, are thus not known. Coloration is mostly uniform brown in varying density, but some specimens (e.g., Fig. 13) bear one or more pale spiral bands. For details of the radula, see Discussion below.

Fig. 24. Lirabuccinum fuscolabiatum, shell sections through lip (A) and penultimate whorl (B), ANSP 244729. Fig. 25. Lirabuccinum musculus, shell sections through lip (A) and penultimate whorl (B), ANSP 424657, from type locality. Fig. 26. Lirabuccinum dirum, shell sections through lip (A) and penultimate whorl (B), Annette Island, Alaska, ANSP 181433. Figs. 24–26 at the same scale. 24 P. Callomon & A. S. Lawless

Discussion

The small buccinid genera of the northern Pacific have been partially revised in recent years, but there is considerable variation in the treatment of individual species. In the present group Vermeij (1991) raised the genus Lirabuccinum with the type species Buccinum dirum Reeve, 1846, which had previously been placed in Searlesia Harmer, 1914. The latter genus is well represented in the Pliocene of the northeastern Atlantic, but apparently belongs in the Muricidae, as it shares affinities in the shape of the adult lip and canal with genera such as Nucella. In addition to L. dirum, Vermeij included the Recent Searlesia constrictum Dall, 1918 and Fusus coreanicus E. A. Smith, 1875. The latter was correctly placed in the fasciolariid genus Fusolatirus by Snyder & Callomon (2005). Vermeij treated Fusus modestus Gould, 1860 as valid in transferring it to Lirabuccinum, but it is a primary junior homonym of F. modestus Philippi, 1844. Some authors (e.g., Pilsbry, 1901; S. Hirase, 1934) had already deduced this and treated Fusus fuscolabiatus E. A. Smith, 1875 as the next available name for Gould’s modesta, but others (e.g., Kuroda & Habe, 1952) considered fuscolabiatus to be a subspecies. From the types, figured here, the present authors judge fuscolabiatus, modestus and constrictus to be synonymous, with Smith’s being the oldest available name. Amano and Vermeij (2003) adopted fuscolabiatus as the valid name for Gould’s modestus, and added Euthria hokkaidonis Pilsbry, 1901 to its synonymy, though without examining the type material. In common with most groups whose embryos develop in capsules, members of Lirabuccinum share a small, paucispiral protoconch that typically lacks a terminal varix. They also feature strong axial sculpture on the early whorls, and a leaf-shaped operculum with a terminal nucleus. The last character is typical of several small buccinid genera, and is shared with certain fasciolariids of the subfamily Peristerniinae that also have similar shell morphology. The presence of anterior columellar plaits usually serves to distinguish small fasciolariids from buccinids, but radula characters can also be used to separate the two groups.

Shell structure All the species examined here have shells that are composed of two layers, but wide differences in structure separate L. dirum from the others. In the Western Pacific species, both layers are relatively thin and the shell is thus proportionately lighter, as shown by the disparity in shell weight / size ratio between them and L. dirum: musculus average 0.045 g/mm; range 0.039 g/mm – 0.06 gm/mm; n = 20 fuscolabiatum average 0.046 g/mm; range 0.034 g/mm – 0.06 gm/mm; n = 13 dirum average 0.105 g/mm; range 0.043 g/mm – 0.21 gm/mm; n = 26 Shell thickness in L. dirum and L. fuscolabiatum varies considerably, in the latter case even among specimens in a single lot. L. musculus shows a similar overall range of thickness to that of L. fuscolabiatum but the distribution of values is more concentrated around the mean. Another major difference between L. dirum and the other Recent species is in the arrangement of the internal lirae. L. fuscolabiatum and L. musculus have multiple separate banks of lirae of varying length that are spread throughout the interior. These are generated independently of the external spiral sculpture, though the animal apparently takes clues from the latter in determining their position and distribution. The lirae are not deposited continuously, but tend to be present where the outer shell layer forms an axial feature such as a rib or a growth break. A bank of lirae is usually also located a short distance from the edge of the lip in fully adult specimens (Fig. 14C). Lirae seem therefore to be deposited only when spiral growth slows temporarily or ceases altogether. Comparison of Figures 24A and 25A shows that L. fuscolabiatum and L. musculus share similar positioning of both external cords and internal lirae at the aperture, though the degree of expression is different. A New Species of Lirabuccinum (Gastropoda: Buccinidae) 25

By contrast with the western Pacific species, the shell of L. dirum is of more complex construction, with a thick lamellar outer layer (Fig. 26). Its internal lirae are long and continuous, though also constructed independently of the outer layer. The inner shell layer (Fig. 26B) is of more complex composition than that of the other species examined here. It features areas of increased density that correspond in position to the troughs between the external cords. In cross section these can be seen to be infilled by shell material whose structure is fan-shaped. This contrasts with the “herringbone” cross-section of oblique parallel structures in the western Pacific species. The inner layer in L. dirum is reduced or absent in the last one-third whorl (Fig 26A), and the internal spiral sculpture in this area is thus simply the impression of the external cords. The smooth outer surface of the shell at this point is apparently achieved by filling in the troughs between the cords, a phenomenon not seen in the other species. These differences in shell structure might represent a sufficient degree of divergence between the two groups to warrant their separation at generic level, but in view of the similarities in radular features and general anatomy, examinations of the fossil species identified by Amano and Vermeij will be necessary to establish this with certainty. Interestingly, the relatively greater shell thickness of the more northerly L. dirum is at odds with Amano and Vermeij’s proposal that heavier and more robust shells would be found in species within this group that inhabit warmer waters.

Radula The radulae of the species examined here (Figs. 18–23) share a similar base plan. That of L. musculus is particularly interesting in that examples taken from adult specimens within the same lot have either three or four cusps on the rachidian tooth (Figs. 21–23), and the morphology of the lateral teeth can vary within the same radula (Figs. 23A, 23B). Tian et al. (2009: figs. H, I, as Plicifusus sp.) illustrated two radulae and identified them as belonging to this species. Their fig. H has five teeth on the rachidian and three equally developed cusps on each lateral, leading the present authors to question whether it represented L. musculus. The shell was not figured. The identification was confirmed by Ms. Tian from images of L. musculus sent by the present authors, but her specimens have not been examined and this identification remains in doubt. The radula in figure I of Tian et al. was cited as Plicifusus sp. species too, but it bears eight cusps on the rachidian and five on each lateral, and clearly does not represent L. musculus.

Acknowledgements

The authors would like to thank Mr. Donald Dan of Fort Myers, Florida for negotiating the recovery of live-taken specimens of L. musculus, and Dr. Martin Avery Snyder (ANSP) for his material support in obtaining the types and further material. We also thank Mr. Dan for his generous donation of part the type material and the majority of the dry specimens examined. Dr. Babs Rinkel (ANSP) took some of the radula pictures. Dr. K. Hasegawa (NSMT) provided preserved specimens and extensive data from the NSMT collections, as well as valuable discussions. Harry Taylor (BMNH) photographed the types of L. fuscolabiatus, and data on that institution’s collections were provided by Kathie Way and Andreia Salvador. This paper benefited greatly from earlier work by Peter Stahlschmidt, Roland Hadorn and Koen Fraussen, who are thanked for their kind collaboration.

References

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Amano, K. & Vermeij, G. J. 2003. Evolutionary adaptation and geographic spread of the Cenozoic buccinid genus Lirabuccinum in the North Pacific. Journal of Paleontology 77: 863–872. Dall, W. H. 1918. Notes on Chrysodomus and other mollusks from the north Pacific Ocean. Proceedings of the United States National Museum 54 (2234): 207–234. Dall, W. H. 1921. Summary of the marine shell-bearing mollusks of the northwest coast of America, from San Diego, California, to the Polar Sea, mostly contained in the collection of the United States National Museum, with illustrations of hitherto unfigured species. United States National Museum Bulletin (112): 217 pp., 22 pls. Gould, A. A. 1860. Descriptions of shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proceedings of the Boston Society for Natural History 7: 323–336. Habe, T. 1961. Coloured Illustrations of the Shells of Japan (II). xii + 183 pp. Hoikusha, Osaka. Harmer, F. W. 1914–19. The Pliocene of Great Britain, being supplementary to S. V. Wood’s monograph of the Crag Mollusca. Volume 1. Monograph of the Palaeontographical Society 67 (4): 1–461, pls. 1–44 (1–200, pls. 1–24, 1914; 201–302, pls. 25–32, 1915; 303–461, pls. 33–44, 1918; title page & index, 1919). Higo, S. & Goto, Y. 1993. A Systematic List of Molluscan Shells from the Japanese Is. and the Adjacent Area. 3 + xxii + 693 pp., bibliography 13 pp., index 149 pp. Elle Corporation, Yao. (in Japanese) Higo, S., Callomon, P. & Goto, Y. 2001. Catalogue and Bibliography of the Marine Shell-bearing Mollusca of Japan. Type Figures. 208 pp. Elle Scientific Publications, Yao. Hirase, S. 1934. A Collection of Japanese Shells with Illustration in Natural Colours. (14) + 217 pp. Matsumura Sanshodo, Tokyo. (in Japanese) Hirase, Y. 1908. On Japanese Mollusca (14). Conchological Magazine 2: 35–45 (J), 8–9 (E), pl. 25. Johnson, R. I. 1964. The Recent mollusca of Augustus Addison Gould. United States National Museum Bulletin (239): 182 pp., 45 pls. Kinoshita, T. 1934. “Hokkaido-san Kai-rui Moku-roku [Catalogue of shells of Hokkaido]” 1. Suisan Chosa Hokoku [Fisheries Survey Reports] (33): 31 pp., 10 pls. (in Japanese) Kinoshita, T. 1937. “Hokkaido-san Kai-rui Moku-roku [Catalogue of shells of Hokkaido]” 2. Suisan Chosa Hokoku [Fisheries Survey Reports] (41): 31 pp., 10 pls. (in Japanese) Kosuge, S. 1972. Illustrations of Type Specimens of Molluscs Described by William Healey Dall. (2) + 29 pls. S. Kosuge, Tokyo. Kuroda, T. & Habe, T. 1952. Check List and Bibliography of the Recent Marine Mollusca of Japan. 210 pp. Leo Stach, Tokyo. Kuroda, T. & Kinoshita, T. 1951. Icones [sic] of marine and plants of Hokkaido, Mollusca no. 1. A catalogue of marine molluscan shells of Hokkaido. Bulletin of Hokkaido Regional Fisheries Research Laboratory (2): 40 pp. (in Japanese) Min, D. K., Lee, J. S., Koh, D. B. & Je, J. G. 2006. Mollusks in Korea. 569 pp. Min Molluscan Research Institute, Seoul. (in Korean) Okutani, T. 2000. Buccinidae. In: Okutani, T. (ed.), Marine Mollusks in Japan, pp. 452–499. Tokai University Press, Hadano. Pilsbry, H. A. 1895. Catalogue of the Marine Mollusks of Japan. viii + 196 pp., 11 pls. F. Stearns, Detroit. Pilsbry, H. A. 1901. New Japanese marine, land and fresh-water Mollusca. Proceedings of the Academy of Natural Sciences of Philadelphia 53: 385–408, pls. 19–21. Reeve, L. A. 1846. Monograph of the genus Buccinum. Conchologica Iconica 3: 14 pls. Smith, E. A. 1875. A list of the Gasteropoda collected in Japanese Seas by Commander H. C. St. John, R. N. Annals and Magazine of Natural History, 4th Series 16: 103–115. Snyder, M. A. & Callomon, P. 2005. On some Fusolatirus from Japan and the Philippines, with description of a new species (Gastropoda: Fasciolariidae). Venus 63: 109–119. Tian,Y., Zhang, S. & Chang, Y. 2009. The radulas research of Buccinidae from the Yellow Sea and Bo-hai Sea. Marine Sciences 33 (10): 54–58. (in Chinese) Vermeij, G. J. 1991. Generic identity and relationships of the northeastern Pacific buccinid gastropod Searlesia dirum (Reeve, 1846). The Veliger 34: 264–271.

(Received February 15, 2012 / Accepted April 27, 2012) A New Species of Lirabuccinum (Gastropoda: Buccinidae) 27

1新種の記載を伴う北太平洋産スジマキイソニナ属の現生種の再検討 （腹足綱：エゾバイ科）

Paul Callomon・Amanda S. Lawless

要 約

主に貝殻と歯舌の形態に基づいてスジマキイソニナ属（新称） Lirabuccinum Vermeij, 1991の現生種の再 検討を行い，黄海から見出された 1新種を記載した。さらに，関連するタクサのタイプを検討し， Searlesia constricta Dall, 1918, Euthria hokkaidonis Pilsbry, 1901 と E. fuscolabiata E. A. Smith, 1875のレクト タイプを指定した。 Lirabuccinum dirum (Reeve, 1846) スジマキイソニナ 属のタイプ種，カリフォルニアからアラスカまでのアメリカ西岸に分布。 Lirabuccinum fuscolabiatum (E. A. Smith, 1875) エゾイソニナ 北海道から東北沿岸太平洋側，日本海，および朝鮮半島南部に分布。土佐湾からも記録がある。 Fusus modestus Gould, 1860［ non philippi, 1844］トバイソニナ，Searlesia constricta Dall, 1918チョウセンイソニ ナは異名。 Lirabuccinum hokkaidonis (Pilsbry, 1901) ホソエゾイソニナ（新称） 本種はエゾイソニナの亜種，あるいは近年は主に異名として扱われてきた。今回，タイプ標本を初めて 図示し，多くの標本を比較することにより，両者は独立した種であることが明らかと なった。本種はエゾ イソニナよりも細長く，縦肋がより細く密に並ぶ。これまで北海道北西岸から男鹿半島の間の海域からの み採集されている。 Lirabuccinum musculus n. sp. コネズミツノマタ（新称） 見かけ上イトマキボラ科の種に類似するが，軟体部の外部形態と歯舌の形態から本属に含まれることが 分かった。タイプ産地（山東省威海沖の黄海，水深 30～ 60 m）からしか知られていない。 これらの種を貝殻の形態で詳しく比較すると，まず貝殻の厚さでスジマキイソニナが北西太平洋産の 3種と著しく異なる（前者の方が厚い）。また，貝殻断面でみた殻口内の螺状襞の構造などにも両者に明 らかな違いが認められ，太平洋の両岸で大きく分化している可能性が示された。しかし，歯舌や軟体部外 部形態の違いに大きな違いがないことから，属レベルで区別するためには化石種との比較などのさらなる 証拠が必要である。