Gulella menkeana (Pfeiffer, 1853)

Herbert, D. G. & Rowson, B., 2011, Pupa menkeana Pfeiffer, 1853, type species of the speciose land snail genus Gulella Pfeiffer, 1856: correction of longstanding PLVLGHQWL ¿ FDWLRQ DQG GHVLJQDWLRQ RI QHRW \ SH (Mollusca: Eupulmonata: Streptaxidae), African Invertebrates 52 (2), pp. 233-233 : 234-237

publication ID

https://doi.org/ 10.5733/afin.052.0201

persistent identifier

https://treatment.plazi.org/id/03EB87F7-FF87-FF85-1EAD-6D04FC41FA7A

treatment provided by

Felipe

scientific name

Gulella menkeana (Pfeiffer, 1853)
status

 

Gulella menkeana (Pfeiffer, 1853) View in CoL View at ENA

Pupa menkeana: Pfeiffer 1853: 552 View in CoL , No 161. Type loc.: Port Natal [= Durban, South Africa].

Ennea menkeana: Pfeiffer 1856 b: 61 ; idem l8ƽ9 LQ l8ƽ4±l86Ɵ: ll³, SO. ³2, ¿JV ³±ƽ.

Pfeiffer (1853) described Pupa menkeana from material in the collection of German conchologist K.T. Menke (1791–1861) and gave Port Natal [=Durban, South Africa] as the only locality.After Menke’s death, his collection was sold to a natural history dealer, M.J. Landauer of Frankfurt, and dispersed via retail sale to private collectors ( Zilch 1958). Thereafter, the location of the original material of G. menkeana has remained unknown and Connolly (1939: 39) stated ‘the type appears to be lost’. However, he LGHQWL¿HG WZR VKHOOV LQ WKH µ%HUOLQ 0XVHXP¶ (=0+%) DV µSDUDW\SHV¶ DQG EDVHG KLV GHVFULSWLRQ RI WKH VSHFLHV RQ RQH RI WKHVH, DOVR SURYLGLQJ D ¿JXUH.,Q WHUPV RI ORFDOLW\ data, he repeated only the ‘Port Natal’ locality. In this same work (p. 39), Connolly discussed Gulella albersi (Pfeiffer, 1855) View in CoL , stating that this was ‘merely a large edition of menkeana, ZLWK ZKLFK LW LV SUREDEO \ FRQVSHFL¿F¶.)RU G. albersi Connolly View in CoL cited, in addition to the type locality, several localities on the KwaZulu-Natal south coast (see QRWH EHORZ UHJDUGLQJ W\SH ORFDOLW\ RI WKLV VSHFLHV).,W LV &RQQROO\¶V GHVFULSWLRQ DQG ¿‒ gure of the ZMHB paratype and his interpretation of G. menkeana that has informed VXEVHTXHQW LGHQWL¿FDWLRQ DQG GLVFXVVLRQ RI WKLV VSHFLHV DQG LWV GLVWULEXWLRQ ($LNHQ 1995; Herbert & Kilburn 2004), and the belief that G. albersi View in CoL is a junior synonym.

In the process of assembling a formal synonymy and list of citations for Gulella menkeana , and providing illustrations of the relevant type specimens, we have disco- YHUHG ¿UVWO\, WKDW WKH =0+% SDUDW\SHV GR QRW FRUUHVSRQG ZLWK WKH ¿UVW ¿JXUH RI WKH VSHFLHV SURYLGHG E\ 3IHLIIHU (l8ƽ9 LQ l8ƽ4±l86Ɵ: SO. ³2, ¿J. 4, KHUH UHSURGXFHG LQ)LJ. l$), DQG VHFRQGO\ WKDW WKHUH DSSHDUV WR EH QR MXVWL¿FDWLRQ IRU FRQVLGHULQJ WKHP to be paratypes in the current sense of the Code. They were part of the collection of J.C. Albers, who evidently obtained them from R.J. Shuttleworth. There is no label to indicate that they were ever part of the Menke collection or that they represent type material of any kind (Glaubrecht pers. comm. 24.iii.2011). Why Connolly should have

FRQVLGHUHG WKHP WR EH SDUDW\SHV LV QRW NQRZQ DQG KH ZDV HYLGHQWO\ QRW MXVWL¿HG LQ VR doing.

When compared with Pfeiffer’s illustration (Fig. 1A) the upper labral tooth of the Albers specimens (Figs 1B, 1C) is a far less robust structure. It is smaller than the lower labral tooth and does not have a basal buttress on its upper side that lies almost SDUDOOHO WR WKH SDULHWDO ODPHOOD. &RQYHUVHO\, WKH ORZHU ODEUDO WRRWK LQ 3IHLIIHU¶V ¿JXUH LV smaller than the upper one and is clearly inset. In addition, the basal tooth is large and WULJRQDO LQ 3IHLIIHU¶V ¿JXUH, EXW QDUURZ LQ WKH $OEHUV VSHFLPHQV. 7KH FROXPHOOD ODPHOOD LV SRRUO\ GH¿QHG LQ 3IHLIIHU¶V ¿JXUH, EXW WKH /DWLQ GHVFULSWLRQ, DOWKRXJK QRW GHWDLOHG LQ terms of apertural tooth morphology, stated that the second tooth (what is now termed the columella lamella – he worked anticlockwise, starting with the parietal lamella) is ‘ excavata profunde ad columellam ’ [deeply excavated at/toward the columella]. This description does not match the columella lamella of the Albers specimens in which this structure takes the form of a horizontal ridge-like tooth. In contrast, in the original

)LJ. l. ($) ¿JXUH RI Pupa menkeana (as Ennea ) JLYHQ E\ 3IHLIIHU (l8ƽ9 LQ l8ƽ4±l86Ɵ: SO. ³2, ¿J. 4); (%, C) ZMHB specimens considered by Connolly (1939) to be paratypes of P. menkeana Pfeiffer, 1853 , length 13.5 mm and 13.6 mm (ZMHB 56871); (D) lectotype of Pupa albersi Pfeiffer, 1855 , ‘ Cape Natal, Mus. Cuming’, length 15.3 mm (NHMUK 20110169); (E) Senckenberg Museum specimen ¿JXUHG DV Gulella menkeana E\ =LOFK (l96Ɵ, LQ l9ƽ9±l96Ɵ: ƽ7l, ¿J. 2ƟƟƟ), µ1DWDO¶, OHQJWK lƟ PP (SMF 83755, photograph S. Hof); (F, G) P. menkeana Pfeiffer, 1853 , neotype, Burman Bush, Durban, length 9.84 mm, diameter 5.05 mm (NMSA W7943/T2670).

description of G. albersi, Pfeiffer (1855) described the columella lamella as ‘ compressa, prominentiae umbilicali transverse imposita ¶>ÀDWWHQHG, SRVLWLRQHG WUDQVYHUVH WR WKH umbilicus] which is an apt description of this structure in the Albers specimens. In terms of size, these specimens (length 13.5 and 13.6 mm) are also closer to G. albersi (length given as 15 mm) than they are to G. menkeana (length given as 11 mm). In fact, these Albers specimens at ZMHB exhibit all the features of G. albersi and their LGHQWL¿FDWLRQ DV G. menkeana is consistent with neither the original description nor the ¿UVW LOOXVWUDWLRQ RI WKDW VSHFLHV. 7KH\ DUH HYLGHQWO\ UHIHUDEOH WR G. albersi (lectotype [designated Connolly 1939: 39] illustrated in Fig. 1D), thus explaining Connolly’s view that G. albersi was merely a large edition of G. menkeana . 7KH GHVFULSWLRQ DQG ¿JXUH of G. menkeana show it to possess characters distinct from those of G. albersi and the two names should no longer be considered synonyms. This conclusion is further VXSSRUWHG E\ WKH IDFW WKDW 3IHLIIHU GLVFXVVHG DQG ¿JXUHG G. albersi in the same work LQ ZKLFK KH ¿JXUHG G. menkeana IRU WKH ¿UVW WLPH (3IHLIIHU l8ƽ4±l86Ɵ), FOHDUO\ LQ‒ dicating that he considered them to be different species. Thus Connolly’s concept of G. menkeana ZDV EDVHG RQ PLVLGHQWL ¿HG VSHFLPHQV ZLWK QR W\SH VWDWXV. &RQVHTXHQWO\, PDWHULDO FROOHFWHG VXEVHTXHQW WR KLV PRQRJUDSK (&RQQROO\ l9³9) DQG LGHQWL¿HG LQ DF‒ cordance with his description of G. menkeana LV PLVLGHQWL ¿HG DQG LQ IDFW UHSUHVHQWV G. albersi ( Aiken 1995; Herbert & Kilburn 2004; Rowson et al. 2010). The question that then arises is — what is the real Gulella menkeana ?

WHAT IS THE REAL GULELLA MENKEANA ?

In the absence of authentic type material of Pupa menkeana , we have only Pfeiffer’s brief original description (Pfeiffer 1853), and his subsequent illustration (reproduced in Fig. 1A) to guide us in determining the true identity of this taxon. Other treatments and ¿JXUHV RI WKH VSHFLHV, SULRU WR &RQQROO\¶V PRQRJUDSK (H.J. 6RZHUE\ l878; 7U\RQ l88ƽ; Möllendorff & Kobelt 1904 in 1903–1905), are of little value since these largely repeat RU DEEUHYLDWH 3IHLIIHU¶V HDUOLHU GHVFULSWLRQ DQG FRS\ KLV ¿JXUH. 0RUH UHFHQW LOOXVWUDWLRQV of specimens in European museums, most probably collected in the late 1800s or early l9ƟƟV (=LOFK l96Ɵ LQ l9ƽ9±l96Ɵ: ƽ7l, ¿J. 2ƟƟƟ; 6FKLOH\NR 2ƟƟƟ: ¿J. lƟ67$) VKRZ D species with a large, buttressed upper labral tooth, suggesting that the early European FRQFHSW RI WKH VSHFLHV ZDV LQ DFFRUGDQFH ZLWK WKH RULJLQDO ¿JXUH DQG DW YDULDQFH ZLWK Connolly’s later interpretation (Connolly 1939). However, the specimens concerned ZHUH QRW W\SHV DQG WKH LOOXVWUDWLRQV DUH WKXV QRW GH¿QLWLYH.,Q UHDOLW\, D SKRWRJUDSK RI the specimen illustrated by Zilch (1960) reveals it to be a specimen of Gulella wahlbergi ( Krauss, 1848) (Fig. 1E, courtesy of R. Janssen) and earlier labels written by Werner Blume identify it as such (Janssen pers. comm. 13.iv.2011).

$SHUWXUDO GHQWLWLRQ LV FULWLFDO LQ WKH LGHQWL¿FDWLRQ RI Gulella species (e.g. Connolly 1939; Verdcourt 1962; Herbert & Kilburn 2004) and, as already emphasised, the form of the upper labral tooth and its juxtaposition almost parallel to the parietal lamella, as well as the smaller size and inset position of the lower labral tooth, are perhaps the PRVW VLJQL¿FDQW IHDWXUHV HYLGHQW LQ 3IHLIIHU¶V ¿JXUH RI G. menkeana . Such a pattern of labral dentition is shown by several other Gulella species, including other similarlysized, axially ribbed species found in the Durban area, namely G. adamsiana (Pfeiffer, 1859) and G. wahlbergi .

The current view of G. adamsiana is that it is a relatively widely distributed taxon (north-eastern Eastern Cape to northern KwaZulu-Natal, from the coast to altitudes of ca 1300 m) and it correspondingly exhibits considerable variation in size, shell proportions and strength of apertural dentition (Bruggen 1980; Herbert & Kilburn 2004). Some of this variation, particularly shell size, may be linked to differences in habitat, specimens from drier thornveld habitats at inland localities being smaller than those from more mesic coastal forests. However, the format of the apertural dentition remains essentially the same, and although the strength and shape of the individual apertural teeth may vary, there appears to be no clear pattern in this variation. The shells illustrated in Fig.2 View Fig , including type specimens of G. adamsiana and its various synonyms are illustrative of this variation. We concur with Burnup (in Connolly 1932) that G. socratica (Melvill & Ponsonby, 1893) is based on a deformed specimen of G. adamsiana . The species is evidently prone to abnormalities ( Warren 1933; Bruggen 1980).

Specimens referable to this concept of G. adamsiana , collected in Durban (the type locality for Pupa menkeana ), FORVHO\ UHVHPEOH 3IHLIIHU¶V ¿JXUH RI Pupa menkeana and are concordant also with the original description. We believe that these can legitimately be considered to represent the species named Pupa menkeana by Pfeiffer (1853). Since this description predates that of Pupa adamsiana Pfeiffer, 1859 , the latter must be considered a junior synonym. So as to stabilise this nomenclature we designate as neotype for Pupa menkeana a specimen from this Durban population (see below).

Krauss’ G. wahlbergi DOVR UHVHPEOHV 3IHLIIHU¶V ¿JXUH RI G. menkeana and Bruggen (1980) has noted the considerable similarity between the former and G. adamsiana . However, he observed that G. wahlbergi differs (inter alia) in having a relatively narrow basal denticle, in the form of an in-running ridge as opposed to a trigonal or subquadrate, transversely-set peg (see also Connolly 1939; Herbert & Kilburn 2004). 3IHLIIHU¶V ¿JXUH RI G. menkeana clearly shows the basal denticle as a trigonal structure like that of many G. adamsiana specimens and unlike that of G. wahlbergi . We follow Bruggen (1980) in considering Helix fanulus Pfeiffer, 1856 , from ‘Port Natal’ which Connolly (1939) associated with G. adamsiana, WR EH DQ XQLGHQWL ¿DEOH MXYHQLOH Gulella and thus a nomen dubium .

An updated synonymy for G. menkeana incorporating these nomenclatural changes LV JLYHQ EHORZ.,Q VR UHGH¿QLQJ WKH VSHFLHV, ZH DUH DZDUH WKDW DGKHUHQFH WR WKH RULJLQDO concept of G. menkeana PLJKW EH FRQVLGHUHG WR FRQÀLFW ZLWK SUHYDLOLQJ XVDJH RI WKH name. However, the species has been rarely mentioned in the literature, beyond mere mention of the name as the type species of Gulella . We are aware of only three instances where the species, as conceived by Connolly (1939), has been cited subsequently in print ( Aiken 1995; Herbert & Kilburn 2004; Rowson et al. 2010). Conversely, the original concept of the species has not completely fallen out of use and was employed by Schileyko (2000). Since both concepts of the species have been employed in relatively recent times, it is logically correct to expunge the one based on an error and to employ WKH QDPH LQ D PDQQHU FRQVLVWHQW ZLWK WKH RULJLQDO GHVFULSWLRQ DQG ¿JXUH.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Stylommatophora

Family

Streptaxidae

Genus

Gulella

Loc

Gulella menkeana (Pfeiffer, 1853)

Herbert, D. G. & Rowson, B. 2011
2011
Loc

Ennea menkeana

: Pfeiffer 1856: 61
1856
Loc

menkeana

: Pfeiffer 1856
1856
Loc

G. menkeana

: Pfeiffer 1856
1856
Loc

menkeana

: Pfeiffer 1853: 552
1853
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