VENUS 60 (1-2): 7-14, 2001

New Records of Mitriform Gastropods from Japan with with Description of 怜 ・xillum (Pusia) charlesi n. sp. (: (Neogastropoda: Muricoidea: Costellariidae)

Hans Turner1 and Paul Callomon2 1CH 6821 Ravia, Switzerland; [email protected] 2Department 2Department af Malacalagy, Academy af Natural Sciences, 1900 Par. わvay, Philadelphia, PA 19103 1195 U.S. U.S. A.; [email protected]

Abstract: Abstract: New additions to the Japanese marine molluscan fauna are her 巴 recorded: Neacancilla Neacancilla kayae Cemohorsky, 1978, hitherto known only from the Hawaiian Islands,

Vexillum Vexillum (Castellaria) delicatum (A. Adams, 1853) known from th 巴 tropical Indo- West Pacific,

組 d V. (Nadicastellaria) sauternesense Suduiraut, 1997 known from the Philippines. V. (Pusia) charlesi charlesi n. sp. was previously known only as an undescribed species from the Philippines, but

has has recently also been found in Japan and is here described. Thal αm， 似 marrowi Cernohorsky, 1980, 1980, originally described from Okinawa, is recorded from th 巴 Kii Peninsula, central Honshu.

Keywords: new records from Japan, new species, Mitrida 巴， Costellariidae

Introduction

The extensive molluscan collection of Mr. Kazutaka Noda of Gobo, Japan has so far yielded three three new Costellariid species. Vexillum (Costellaria) multitriangulum Salisbury & Callomon, 1998 was followed by V. ( C.) nodai and V. (C. ）民 forti, both of Turner & Salisbury, 1999. The present authors authors recently r・eceived for examination some further unidentified Costellariids and Mitrids from

Mr. Noda, Mr. Mitsuo Chino and Mr. Ted Baer. All had been collected on the Kii Peninsula in cen 同 tral tral Honshu, Japan; one species from beach drift, the oth 巴rs from depths of b巴tween 70 and 180 m. The present material represents one species new to science, thr 巴巴 hitherto not recorded from Japan and one range extension.

Abbreviations

AIM: Auckland Institute and Museum, New Zealand BMNH: The Natural History Museum, London, United Kingdom MHNG: Museum d ’Histoire naturelle, Geneva, Switzerland MNHN: Museum national d ’Histoire naturelle, Paris, France NSMT: National Science Museum, Tokyo, Japan SMTD: Staatliches Mus 巳um ftir Tierkunde, Dresden, Germany Coll.: Coll.: Collection of

Systematics

Ord 巴r NEOTAENIOGLOSSA Haller, 1882 Suborder Suborder NEOGASTROPODA Thiele, 1929 Superfamily Superfamily Muricoidea Rafinesque, 1815 Family Swainson, 1831 8 H. Turner & P. Callomon

Genus Neocancilla Cemohorsky, 1966 T）戸 species: Volut α， papilio Link, 1807 (by original designation).

Neocancilla Neocancilla kayae Cemohorsky, 1978 (Figs. (Figs. 1, 2)

Type locali 砂： Pokai Bay, Oahu, Hawaiian Islands, 110-128 m. Material Material examined: Off Minabe, western coast of Kii peninsula, central Honshu, approx. 100 100 m depth; 4 specimens 9.2 mm, 8.9 mm, 8.3 mm & 7.9 mm in shell length. Coll. K. Noda. Off Cap 巴 Shio (Shionomisaki), Kii Peninsula, dredged at 180 m on rubble and sand with many dead shells, shells, April 1998 :1 specimen, 13.4 mm. Coll. M. Chino. Remarks: This is apparently the first recorded occu 汀 ence of this species outside the Hawaiian Islands. Islands. N. kayae is a rare species, hitherto known from fewer than a dozen specimens. In Hawaii, specimens specimens of up to 14 mm in shell length have been recovered from depths of ov 巴r 110 min a biotope biotope of coralline algae and sand. N. kayae differs considerably in sculpture from the type species of of Neocancilla and is here only provisionally assigned to this genus pending study of radular mor- phology phology and other features. The present specimens agree with the holotyp 巴（ Fig. 1) of N. kayae in general appearance; though though the colouration is less vivid, the schematics of the patterning are the same. The number and spacing spacing of both spiral and axial sculptural elements is also identical with those of the holotype. However, However, while 白e nodes formed by the intersection of the axial ribs and spiral grooves are pustu- lose lose in Hawaiian specimens, in the present mat 巴rial they are distinctly flattened and the shells thus have have a smoother appearance overall. The protoconch is similar in morphology to that of the holo- type type but is pale off-white in the Japanese specimens rather than dark brown. Both these features fall within within the rang 巴 of intraspecific variation accepted by most authors in the Mitridae, and 訂 c not held held h巴 re to be grounds for separation at any level.

Family Family Costellariidae MacDonald, 1860

Genus Vexillum R りding, 1798 Subgenus Subgenus Costellaria Swainson, 1840 T）戸 species: rigida Swainson, 1821 [=Mitra semifasciata Lamarck, 1811] (by monotypy).

Vexillum Vexillum (Costellaria) delicatum (A. Adams, 1853 partim) (Figs. (Figs. 3, 4)

Type locali. 砂・ Cape York (Queensland, Australia), 8 fathoms (15 m) . Material Material examined: Off Shirahama, western Kii Peninsula, central Honshu, approx. 100 m; 2 specimens specimens 25.8 & 23.3 mm. Coll. K. Noda Remarks: This species has hith 巴rto not been identified as a component of the Japanese fauna, possibly possibly due to confusion with the similar V. (C.) sculptile (Reeve, 1845) and V. (C.) obeliscus (Reeve, (Reeve, 1844). In fact, the type material of Mitra delicata A. Adams represents two species. One of of the three syntypes (18.2 × 6.6 mm, aperture 8.1 mm) is V. （仁） sculptile. The remaining two syntypes syntypes (19.l × 6.6 mm & 17.1 × 5.9 mm) are the true V. (C.) delicatum. Hedley (1908: 484- 485, 485, pl. 7, fig. 1) gave a precise redescription of the species, based on the largest syn type ( 19 .1 mm, lectotype, lectotype, Fig. 3) which is worn and faded, tog 巴ther with new specimens in better condition from northern northern Queensland. V. （仁） delic αtum differs from the two species mentioned above mainly by its more delicate sculpture featuring promin 巴nt and very na 町 ow axial ribs, which ar 巴 less than half as New Records of Mitriform Gastropods from Japan 9

2a

6c

3

5

Figs. Figs. 1-2. Neocancilla kayae Cernohorsky, 1978. 1. Holotype (AIMfTM - 1355) 8.7 × 3.5 mm; Pokai Bay, Oahu, Hawaiian Hawaiian Ids ., 110-128 m. 2a, 2b. Specimen 9.2 mm; off Minabe, Wakayama Pref., Honshu, ca. 100 m. Figs. Figs. 3-4. Vexillum (Costellaria) delicatum (A. Adams, 1853). 3. Lectotype (BMNH 1967745/1) 19.l × 6.6 mm; Cape York, 8 fathoms (Jukes). 4a, 4b. Specimen 23.3 mm; off Shirahama, Wakayama Pref., Honshu, ca. lOOm . Figs. Figs. 5・6. Vexillum (Nodicostellari α） sauternesense Suduiraut, 1997. 5. Holotype (MNHN) 42.3 × 11.5 mm; Hilutangan Hilutangan Strait , Mactan/Olango Islands ,Philippines, 160 m. 6a, 6b, 6c. Specimen 40.4 x 11.1 mm; off Cape Shio, Kii Peninsula, Honshu , 150 180 m. 10 10 H. Turner & P. Callomon broad broad as the interstices separating them. These cross the spiral cords, which are thereby interrupt- ed. ed. The spiral cords lattice the de 巴p interstices between the axial ribs with bars equal in breadth to the the deep pits sep 但・ating them. 院（ C.) delicatum can also be distinguished by its pattern of three nar- row orange bands on a milk-white base. Each band is of roughly the same width as three spiral

cords; cords; one is situated below th 巴 suture, the second at the p巴riphery, and the third at the base ，巴 nter 『 ing ing the aperture immediately above the columellar folds.

Subgenus Subgenus Nodicostellaria Petuch, 1987 Type Type species: Costellaria kaicherae Petuch, 1979 (by original designation).

Vexillum Vexillum (Nodicostellaria) sauternesense Suduiraut, 1997 (Figs. (Figs. 5, 6)

Type locaU 砂： Hilutangan Strait between 恥factan and Olango Islands, Philippines, 160 m depth, on sand with volcanic stones.

Material Material examined: Off Cape Shio, southern Kii Peninsula, central Honshu, dredged at 150 『 180 180 m by S. Nagai & S. Habu, July 1998; 1 specimen 40.4 × 11.1 mm (T. W. Ba 巴 r coll., Fig. 6) Remarks: This species has hitherto been recorded only from the Philippines. In the original description, description, V. (N.) sauternesense was compared with and differentiated from the Japanese species V. V. (C.) takakuwai Cemohorsky & Azuma, 1974 (Suduiraut, 1997). The latter species features a smaller smaller number of axial ribs and an additional brown spiral band beneath the sutures. The protoconch of the holotype of V. (N.) sauternesense was not described as it was miss- ing, ing, but in the present specimen from off Cape Shio the protoconch is intact. It is papillose and paucispiral, paucispiral, consisting of 1.5 smooth, glassy embryonic whorls (Fig. 6c). V. V. sauternesense is here assigned to the subgenus Nodicostellaria Petuch, 1987 as it agrees agrees with the type species in having a smooth and paucispiral protoconch 組 d teleoconch sculp- ture ture of close-packed and equal-sized spiral and axial ribs, with the intersections of the axial and spi- ral ral elements producing a uniformly nodulose shell surface. Another lndo-Pacific costellarid species which may be assigned to the subgenus Nodicostellaria is V. vandervlerki (Koperberg, 1931).

Subgenus Subgenus Pusia Swainson, 1840 Type Type species: Pusia microzonis (Lamarck) [Sic= Mitra microzonias Lamarck, 1811] (by monotypy).

Vexillum Vexillum (Pu.~ia) charlesi n. sp. (Figs. (Figs. 7-9)

Description: Description: Shell moderate in size for the subgenus, to approximately 17 mm in length; elon gate-fusiform, gate-fusiform, contracted at the base. Ratio of shell height to width variable. Width 31-12-399 もof height. height. Conoidal protoconch of 4 glassy, honey-coloured embryonic whorls. Teleoconch whorls 6- 8 in number; spire sharply acute with nearly straight outline; whorls slightly stepped at the well defined defined sutures. Sculpture: Sculpture: Axial ribs prominent, rounded and polished, somewhat broader than their inter- stices, stices, numb 巴ring 12 on the first whorl, 15-18 on the last, fairly regularly spaced; interstices of the ribs ribs latticed by 6- 7 deeply incised broad spiral grooves; grooves do not bisect th 巴 ribs, and are slightly slightly na 町 ower than the flat bars separating them. Body whorl thin walled, anterior part usually distinctly constricted ；仕 om the periphery towards the the base, axial ribs become narrow and curved, becoming redundant farther ant 巴riorly, their inter- stices stices articulated by 10-12 distinct, deep, wide spiral grooves. On some specimens, axial ribs become 巴ntirely obsolete on the body whorl. Anterior part siphonal including fasciole ornamented New Records of Mitriform Gastropods from Japan 11

Figs. Figs. 7・9. Vexillum (Pusia) charlesi n. sp . 7a, 7b. Holotype (MHNG) 15.0 x 5.2 mm; off Balicasag Id. , Bohol, Bohol, Philippines , 140/160 m . 8. Paratype #9 (11.l × 4.4 mm); off 恥factan Isld., Cebu, Philippines, Philippines, by net 120 m, on sand and rocky bottom . 9. Paratyp 巴＃ 15 (NSMT-Mo 72862) 14.5 × 5.3 5.3 mm; off Kirimezaki, Wakayama Pref., 50-70 m. Fig. Fig. 10 . Vexillum (Pusia) semicostatum (Anton , 1838). Lectotype (SMTD 3152) 8.4 × 3.4 mm ; locality unknown. unknown. Fig.11 . Ve λ ilium (Pusia) corallinum (Reeve, 1845). Syntype (BMNH 1967727/2) 14.7 × 4.9 mm; Isle of Masbate, Masbate, Philippine s. Fig. Fig. 12. Vexillum (Costellaria) aureolineatum H. Turner, 1988. Holotype CTv 位丑 l/G 988101) 16.4 ×6.2mm ; Bohol/Panglao , Philippines , deep water. Figs. Figs. 13-15. Thal αmaxmarrowi Cernohorsky, 1980 . 13. Holotype (AIM/TM-1364) 6.9 × 2.2 mm ; Seragaki, Seragaki, Okinawa , 35 m. 14. Specimen 5.5 × 2.0 mm (apex and anterior end of outer lip bro ken); ken); Cape Shio beach , Kii Peninsula , central Honshu . 15. Specim 巴n5 .1 × 2.1 mm (ap 巴X bro- ken); ken); Cape Shio b巴ach, Kii Peninsula, central Honshu. 12 12 H. Turner & P. Callomon with with 6-8 rounded oblique spiral cords which are partially nodulose, esp 巴cially those which appear as as continuations of the columellar folds. Columella with four folds, anteriorly decreasing in size but increasing increasing in obliquity. Aperture na 汀 ow, lirate shorter within, than the spire (41-46% of shell length); length); outer lip thin, smooth and rounded, distinctly recurved inward at the base. Siphonal canal short, short, wide and recurv 巴 d dorsally. Siphonal notch not well defined on any sp 巴cimen. Colour Colour pattern variable. Ground colour of shell (including aperture and colum 巴lla) ivory-white,

light light yellow, hon 巴y-yellow, or light to dark orange 『 red; most specimens ornamented with 1町 egu- larly larly arranged white squarish blotches and with a narrow white peripheral spiral band which app 巴ars on the axial ribs of the spire whorls near the sutures. Type local 的：， Off Balicasag Island, Panglao, Bohol, Philippin 臥 at 140-160 m depth. Distribution Distribution and habitat: Philippine Islands: Bohol, Cebu, Mindoro. Japan: Kii Peninsula, cen- tral tral Honshu. Littoral and sublittoral zones to 200 m depth, on sand and broken coral. Type material: Holotype, MHNG 29668 (Fig. 7) length 15.0 mm, width 5.2 mm, aperture 6.4 6.4 mm; off Balicasag Island, Bohol, Philippines, by tangle net, leg. Emmanuel G. d巴 Suduiraut, April April 1990. Paratypes #1-5 from the type locality: #1, 13.0 × 4.8 mm, apertur 巴 5.5 mm and #2, 11.2 × 4.4 mm, aperture 5.0 mm, coll. E. Suduiraut; #3, 11.6 × 4.2 mm, aperture 5.3 mm, coll. H. Turner; Turner; #4, 13.7 × 4.3 mm, aperture 6.0 mm and #5, 12.3 × 4.6 mm, aperture 5.6 mm, coll. T. W. Baer. Baer. Paratypes Paratypes #6-8 from the Bohol Strait, Philippines, shell nets 60-200 m, May 1980; #6, 14.l × 5.5 5.5 mm, aperture 6.3 mm, #7, 12.4 × 4.9 mm, aperture 5.4 mm, and #8, 9.8 × 4.3 mm, aperture 4.7 4.7 mm, coll. M. Marrow. Paratypes #9-10 from off Mactan Island, Cebu, Philippines, by net at 120 120 m, on sand and rocky bottom; #9, 11.l × 4.4 mm, aperture 4.8 mm, coll. E. Suduiraut; #10 13.4 × 5.2 mm, aperture 5.7 mm, coll. M. Marrow. P 訂 atypes 11-13 from Encenada Beach, Puerto Galero, Galero, Mindoro, Philippines, shallow water, l巴g. M. Charles, 1990; #11, 12.2 × 4. 7 mm, aperture 5.7 5.7 mm and #12, 12.1 × 4.3 mm, aperture 5.0 mm, coll. T. W. Baer; #13, 11.3 × 4.1 mm, aper-

ture ture 5.0 mm, coll. H. Turner. Paratypes #14 『 16 from off Kirimezaki, western Kii Peninsula, Honshu, Honshu, Japan, 50- 70 m, in lobster nets; #14, 14.6 × 5.3 mm, aperture 6.6 mm, coll. K. Noda; #15 14.5 × 5.3 mm, aperture 6.3 mm, NSMT-Mo 72862; #16, 11.6 × 4.4 mm, aperture 5.2 mm, coll. H. H. Turner. Paratypes # 17-19, from off Punta Engano, Cebu, Philippines, from nets at approximate- ly ly 180 m, Jun 巴 1978 : #17, 17.2 × 5.9 mm, aperture 6.4 mm; #18, 16.0 × 5.5 mm, aperture 6.8 6.8 mm, and #19, 14.9 × 5.8 mm, aperture 6.7 mm, coll. R. Salisbury. Etymology: Etymology: Named in honour of Mr. Michel Charles of Antananariro, Madagascar who col- lect 巴d the species on Mindoro Island, Philippines, and first brought it to the senior author ’s atten- ti ti on. Remarks: There are several Costellarid species with similar colour patterns. In some respects V. (P.) (P.) charlesi resembles V. (P.) semicostatum (Anton, 1838) (Fig. 10). Both species are found in the Philippines Philippines as w 巴11 as in Japan. V. (P.) semicostatum has a similar reddish brown colour with irreg-

ular ular white blotches, but it differs in having a smoother, more solid shell with flat axial ribs, in con 蜘 sistently sistently bearing a distinct light-coloured peripheral spiral band, and in lacking the distinct basal constriction constriction of the body whorl seen in V. (P.) charlesi. V. V. (P.) charlesi could possibly also be confused with V. (P.) corallinum (Reeve, 1845) (Fig. 11). The latter has a much smoother and more solid shell, however, is livid red in colour and bears white spots spots regularly arranged in a peripheral spiral zone where they are more or l巴ss confined to the axial axial ribs. Lighter and more uniformly coloured variants of V. (P.) charlesi can resemble to some degree degree V. (C.) aureolineatum Turner, 1988 (Fig. 12). The latter species is easily distinguishable by its its pattern of regular golden-brown spiral lines which are uniformly absent in V. (P.) charlesi.

Genus Genus Thala H. & A. Adams, 1853 T）戸 species: Mitra mirifica Reeve, 1845 (by subsequent designation; Cossmann, 1899). N 巴w Records of Mitriform Gastropods from Japan 13

TLn h C3 h K 11QO ハリ a mM 冨， ．，ωwR0gU Cm。） vi03 y 凸 開 o ノ （ 5 一－一日

Type locality: Seragaki, central western Okinawa Island; 35 m, bottom of cliff-face. Material Material examined: Beach at Cape Shio, Kii Peninsula, central Honshu, 1999; 7 specimens, shell shell length 7.0 to 4.9 mm (M. Chino coll., H. Turner coll ふ Remarks: This sp 巴cies has been known to Japanese collectors for some tim 巴， but has b巴巴 n cited as “ Isara sp. (probably undescribed)". The generic name “Isara ” is certainly not appropriate for T. maxmarrowi. The type species of Isara H. & A. Adams, 1853 is Mitr α， glabra Swainson, 1821, a large large and quit 巴 different species normally now placed in Mitra s. str. In the original description (Cernohorsky, (Cernohorsky, 1980: 148-149), T. maxmarrowi was compared with Thala illecebra (Melvill, 1927) from the Straits of Korea which is mηsimilar in size and shape, but which has a considerably stronger stronger sculpture of axial riblets studded with granules. Several specimens from the beach at Cape Shio Shio were sent to the senior author by Mr. Chino for study in November 1999 (Figs. 14-15). Mr. Chino also provided a further Japanese record of T. maxmarrowi: Okinoerabu Island, Amami Islands, Islands, southern Kyushu (specimens in the collection of Mr. Y. Yukita). T. T. maxmarrowi is known to be widely distributed in the Indo-Pacific, from the Mascarene Islands Islands in the Indian Ocean to the Marshall Islands in the Central Pacific.

Acknowledgements

The authors ar 巴 grateful to Mr. Kazutaka Noda (Gobo, Wakayama Prefecture, Japan) for making mate- rial rial from his collection available for study and for the donation to the NSMT of a paratype of the new species species described herein; to Mr. Emmanuel G. d巴 Suduiraut (Lapu Lapu City, Cebu, Philippines) for his cooperation cooperation over many y巴ars, and in particular for his donation to the MHNG of the holotype of V. (P.) charlesi; charlesi; to Mr. Mitsuo Chino (Kawasaki, Kanagawa Prefecture, Japan) for valuabl 巴 data and for provid- ing ing Japanese names; to Mr. Shingo Habu (Kasukawa, Gunma Prefecture, Japan) for kind and prompt con firmation firmation of data; to Mr. Maxw 巴11 P. Marrow of Beaumaris, Victoria, Australia who made sev 巴ral sp 巴ci- mens of V. (P.) ch αrlesi available for examination, and to Dr. Ted W. Baer (La Croix sur Lutry, Switzerland) Switzerland) for acc 巴ss to his outstanding collection of mitriform gastropods and for photographs. Our spe- cial cial thanks go to Mr. Richard Salisbury (Bois 巴， Idaho) who helped on an early V 巴rsion of th 巴 V. (P.) ch αrlesi description.

References

Adams, A. 1853. Descriptions of fifty-two new species of th 巴g巴nus Mitra, from the Cumingian Collection. Proc. Proc. Zool. Soc. London pt. 19 [1851]: 132-141 Cernohorsky, Cernohorsky, W. 0. 1978. New species of Mitrida 巴， Costellariidae and Turridae from the Hawaiian Islands with with notes on Mitra sphoni in the Galapagos Islands. Nautilus 92: 61-67, figs. 1-12. Cernohorsky, Cernohorsky, W. 0. 1980. The of some Indo-Pacific . Part 8. Rec. Auckland Inst. Mus. 17: 17: 135-152. Hedley, Hedley, C. 1908. Studies on Australian Mollusca. Part X. Proc. Linn. Soc. NS. W. 33: 456-489, pls. 7-10. Salisbury, R. Salisbury, & Callomon, P. 1998. A new Costellarid (: Costellariidae) from the Pacific Ocean. Ocean. La Conchiglia 30(286): 30-33, figs. 1-9. Suduiraut, Suduiraut, E. G. 1997. Description d'une nouvelle esp とcede Costellariidae des Philippines. APEX 12 (4): 117-119, 117-119, figs. 1-5. Turner, Turner, H. & Salisbury, R. 1999. Thr 田 new costellarid species from Japan, Papua New Guinea and other Indo Indo Pacific locations (Neogastropoda ：恥 1uricoidea: Costellariidae). APEX 14 (3-4): 73 80, figs. 1 22.

(Receiv 巴d August 2, 2000 I Accept 巴d February 14, 2001) 14 14 H. Turner & P. Callomon

ナツミオトメ（新種・新称）を含む日本新記録のフデガイ類

H. ターナー. P. カロモン

要約

野田和孝，知野光雄氏ならびに T. Baer の各氏から提供された紀伊半島産フデガイ類の中から， 1 新種 を含む 4 種の日本新記録種と， l種の紀伊半島新記録種が見出された。

Neocancilla Neocancilla kayae Cernohorsky, 1978 ケタセアラフデ（新称） 南部沖水深約 100 m （野田氏採集）。本種はハワイ諸島以外からは初めての記録となる。紀伊半島産の 個体はハワイ産と比べて色彩が鮮やかで，彫刻が弱いが種内変異に収まる。和名は産地の白浜沖ケタ瀬 に因む。

Vexillum Vexillum (Costellaria) delicatum (A. Adams, 1853) マエカワツクシ（新称） 白浜沖水深約 100 m （野田氏採集）。本種はこれまでアミメツクシやタオヤカツクシに混同されていた が，両種よりも彫刻が繊細で乳白色の地に 3 本の細いオレンジの色帯を持つことで区別される。和名は 奄美大島名瀬の前川隆則氏に因む。

Vexillum Vexillum (Nodicostellaria) sauternesense Suduiraut, 1997 ナガイツクシ（新称）

紀伊半島潮岬沖ドレッジ水深 150 ～ 180 m （故永井誠二・土生紳吾両氏採集， Ba 巴r氏蔵）。本種はフィ

リピンから記載され，紀伊半島は 2 番目の産地となる。和名は串本の故永井誠二氏に因む O

Vexillum Vexillum (Pusia) charlesi n. sp. ナツミオトメ（新種・新称） 殻はこの亜属としては中型で殻高約 17 mm ，細長い紡錘形。胎殻は円錐形， 4 層，ガラス質で黄褐色。 成殻の彫刻は，丸みがあって肋間よりもやや太い顕著な縦肋とその肋間にある深い螺溝からなる。殻口 は狭く，殻高の 41 ～ 46% ，軸唇には 4 本の袋がある。水管は短く背部に反り返る。地色は象牙色～白 色から暗澄赤色で，ほとんどの個体は不規則に並ぶ白色斑と周縁に細白帯をめぐらす。和名は日本産の 標本を採集し，提供された漁業者の塩路真佐弘氏の令嬢七海さんに因む。 ホロタイプ：殻高 15.0 mm ，殻径 5.2 mm (MHNG29668 ），フィリピン，ボホール，パリガサ島沖水深 140,...: 140,...: 160 m （模式産地）。 パラタイプ：殻高 14.5 mm ，殻径 5.5 mm (NSMT-Mo72862 ），切目崎沖水深 50 ～ 70 m 。

Thala Thala maxmarrowi Cernohorsky, 1980 ノミテツヤタテ 潮岬打ち上げ（知野氏採集）。本種は沖縄瀬良垣から新種記載されたが，その後インド太平洋域に広く 分布することが明らかになっている。本報告により北限が紀伊半島まで伸長された。