Ptychobela flavidula (Lamarck, 1822)

Li, Bao Quan, Kilburn, Richard N. & Li, Xin Zheng, 2010, Report on Crassispirinae Morrison, 1966 (Mollusca: Neogastropoda: Turridae) from the China Seas, Journal of Natural History 44 (11 - 12), pp. 699-740 : 732-733

Ptychobela flavidula (auctt non Lamarck, 1822)

( Figure 4F )

Material examined

Yellow Sea. Three specimens, CN 40-12 , 36°45′ N, 122°15′ E, silty clay, 20 m, AT, 29 October 1958 ; 1 spm, CN H102 B-12, 36°00′ N, 121°00′ E, sandy mud and gravel, 35 m, B. T., 24 April 1959 ; 2 spms, CN Y275 B-16, 36°30′ N, 122°00′ E, silty clay, 24 m, AT, 12 July 1959 .

ECS. Twenty-eight specimens, CN V311 A-5, 32°00′ N, 122°30′ E, coarse sand and shell debris, 25 m, AT, 24 October 1959 ; 36 spms, VN C50B-27, 32°30′ N, 122°15′ E, fine sand, 27 m, AT, 22 October 1959 ; 3 spms, CN 222-40 , 31°30′ N, 123°00′ E, silt, 59 m, BT, 4 February 1959 ; 10 spms, CN F48 B-10, 30°00′ N, 120°45′ E, silt, 42 m, AT, 8 December 1959 .

Beibu Gulf. One specimen, CN X152 B-17, 19°00′ N, 106°30′ E, 40 m, sand, AT, 26 October 1960 ; 1 spms, CN X172 B-21, 20°00′ N, 108°30′ E, fine sandy mud and slit, 62 m, AT, 21 January 1962 ; 1 spm, CN X192 B-33, 18°30′ N, 106°15′ E, sandy mud and shell debris, 28 m, AT, 11 April 1962 ; 1 spm, CN X192 , 18°30′ N, 106°15′ E, shell debris and sand, 20 m, AT, 11 April 1962 .

SCS. Three specimens, CN K81 B-17, 21°15′ N, 114°00′ E, sand, 52 m, AT, 18 October 1959 ; 1 spm, CN K104 B-59, 20°30′ N, 112°00′ E, sandy mud, 65 m, AT, 28 October 1959 ; 1 spm, CN K102 B-18, 19°30′ N, 112°00′ E, muddy sand, 122 m, AT, 28 October 1959 ; 1 spm, CN K13 B-86, 21°30′ N, 111°30′ E, muddy coarse sand, 39.5 m, AT, 16 February 1960 ; 1 spm, CN S175 B-48, 23°30′ N, 117°30′ E, fine sand, 34 m, AT, 4 January 1960 ; 1 spm, CN K152 B-32, 20°00′ N, 112°30′ E, muddy sand, 101 m, AT, 6 April 1960 ; 1 spm, CN Q203 B-4, 21°24′ N, 109°00′ E, muddy sand, 11 m, AT, 22 April 1960 ; 1 spm, CN X7 AB-20, 19°00′ N, 105°45′ E, muddy sand, 128 m, AT, 11 February 1960 ; 1 spm, CN N15 B-84, 18°15′ N, 108°45′ E, coarse sand, 38 m, AT, 12 March 1960 ; 1 spm, CN K280 B-16, 18°30′ N, 106°30′ E, sand, 40 m, AT, 26 October 1960 .

Measurements

See Table 1.

Distribution

Yellow Sea, ECS and SCS, Beibu Gulf, Nansha Islands.

Remarks

This and several similar species have been commonly misidentified as Pleurotoma flavidula Lamarck, 1822 ( 1822: 92, type loc.: Red Sea), a species only briefly described by its author, without figures or figure references. However, the lectotype of that species in the MHNG (which according to Dr Yves Finet is accompanied by a label in Lamarck’s own handwriting) shows little resemblance to P. flavidula auctt . It has a short, broad siphonal canal and a wide, weakly concave subsutural region (see Figure 4G ), and appears close to Ptychobela concolor ( Smith, 1877) (syntype see Figure 6A ), a rare species apparently known only from Indonesia. Previous misidentifications were probably initiated by early authors following Kiener (1840: 30, pl. 6, fig. 2), who despite having access to Lamarck’s holotype (“Coll. Mass. et Mus.”), illustrated as this species a shell with a long, tapering siphonal canal, very different to the holotype of P. flavidula .

Pleurotoma (Drillia) pseudoprincipalis Yokoyama, 1920 , from the Pleistocene of Japan, sometimes cited as a synonym of P. flavidula , has a well-developed subsutural cord which not only distinguishes the two species at a glance, but indicates that P. (D.) pseudoprincipalis might be an Inquisitor .

References to figures of Pleurotoma flavidula of authors are not given here, as there appear to be several (if not many) similar but undescribed species belonging to this complex. A new name is not proposed because an in-depth study of the speciescomplex is clearly required. The present specimens from China show great variation in shell outline, number of axial ribs, spiral ridges and proportions (see Table 1). This species is abundant in the Yellow Sea, ECS and SCS.

Figures

Figure 4. Species of subfamily Crassispirinae. (A, B) Funa cretea sp. nov. (holotype, Yellow Sea, CN Y285B-59, 29 m, 21.9 × 7.8 m); (C) Inquisitor angustus (ECS, CN V560B-79-1); (D) Inquisitor intertinctus (Beibu Gulf, CN Q62B-4-1); (E) Inquisitor cf. solomonensis (SCS, CN S219B-51); (F) Ptychobela flavidula (Beibu Gulf, CN X192B-33), 1822; (G) lectotype of Pleurotoma flavidula, MHNG 1097/51, Red Sea, 38.8 × 11.5 mm; transparency courtesy of Yves Finet.

Figure 6. (A) Syntype of Pleurotoma (Drillia) concolor Smith, 1877, BMNH 1964227, Moluccas; 42.1 × 11.2 mm; (B) Ptychobela suturalis (Hainan Island); (C, D) Ptychobela resticula sp. nov. (holotype, SCS, CN S208B-42, 83 m, 41.5 × 14.3 m); (E) Ptychobela vexillium (SCS, CN N31B-13).